JEE

The JEE Mains and IPUCET has the same topics in physics, chemistry and mathematics.
While doing preparation, one should know at which level he/she stood in JEE Mains.
If the preparation was wholehearted then you will get admission in NIT. If you fail to perform well in JEE Mains then do the self analysis of the topics and the mistakes made.
If the results are the same but you think you have prepared hard then you have to work on yourself and have some counselling and apply some extra effort.
As far as the level is concerned, IPUCET is easier and comfortable than JEE Mains.
You should solve the previous years' papers. If you can solve the previous years JEE Mains papers easily then you don't need to prepare or take much tension about IPUCET.
So, the answer should include, how you have prepared for JEE Mains? How satisfied are you with the preparations?
At last, go through calculus, thermodynamics, vectors and 3D, optics, mole, atomic structure, biomolecules, alkanes and chemical bonding.
Thank you.
Hope it helped.

The possible answer to this question can be given by yourself only.
Practically, all the topics that are covered in JEE Mains are also covered in AMUEEE and though the level is very easy as compared to JEE Mains so there is no separate preparation needed for the AMUEEE.
The only factor which would be there is (maybe) time difference between both the exams so one can go with thorough revision before appearing for the exam and can solve the previous AMUEEE papers to know the criteria and the points which need focus in the syllabus.
Also, it depends on the student that how he or she is preparing for the JEE Mains.
If he or she prepares wholeheartedly, he/she will qualify JEE Mains with very great marks and will secure a good rank. Also, if they are unable to perform well then also preparations are enough for AMUEEE. If someone has not thoroughly prepared and not studied the fundamentals and the NCERT books, he or she needs to focus on the preparations before taking AMUEEE and need to solve a lot of practise questions, again on the basis of his or her requirements.
Thank you. Hope it helped.

Tamil Nadu has many good coaching centers like:
Aakash: The teachers here are good, but it's very expensive if you compare other JEE institutes some of which are better. It's good for medical preparations though.
FIITJEE: They take a test based on which they divide you into batches, the students performing better are given better batches which sometimes demoralizes the students who dint get into good batches. They only concentrate all attention and focus on these students which I personally disapprove of.
Brilliant Tutorials / Career Launcher : Their performance has been depreciating for a while , they provide you basic mentorship and have good test series , though there have been many cases where people have paid the entire coaching amount but not received any coaching or refund.
BYJU'S CLASSES: They have been doing really well in last couple of years as 161 out of 212 students made it through IIT's last year. I have heard they make classrooms a fun interactive session for their students which works in their favor. Also they have been known to return the entire fee amount if the student does not find them good enough for JEE. The only downside is that they accept only a certain number of students and the batches fill up really fast.
Source - https://www.quora.com/What-are-the-best-IIT-JEE-coaching-centers-in-Chennai

This is a list of coaching centers available:
But this list is not ranked, it just gives all options available. So research a bit before enrolling. Check for reviews on net and talk to some students in those institute.
1. Bansal Institute for Excellence
Bansal have a best coaching classes in Ahmedabad and with the good teachers and faculties.
2. Brainquest Science Academy
Brainquest academy focused on the basic concepts. The faculty totally focused on concepts learning approach Brainquest academy discipline and on time. Due to quality management now Brainquest offers coaching in many courses but its focus has been on IIT JEE since inception.
3. Career Point
Career point is good is good institution in Ahmedabad he teach students by good books and updated syllabus. All teacher are good and experienced in field. Career point has been guiding students for IIT JEE since edges and performance of students at coaching is good.
4. Precept
Precept Academy is effort you put in will determine your successful life in your career and personal life. The teachers have good subject knowledge and are guiding you well.
5. Abhyas
Abhyas is perfect in IIT-JEE, JEE Mains, AIMT by the best faculties, they have experience ever had to introduce to your hidden talents. Although Triumph Academy focus was on CAT coaching's but its gaining popularity brought it in IIT JEE coaching and its doing good for students who are preparing for IIT JEE.
6. Abhyas Practice for IIT-JEE
7. .S.N. Enterprise
8. B.R. Tution Zone
9. Aakash Educational Services Ltd.
10. Nirva Maths Group Tuition
Again: Don't use this as final list, do your own research before enrolling.

This is really a tough question because both of the question paper has its own perks and difficulty.
But according to me JEE is more difficult than BITSAT because JEE has questions asked based on the concepts of the syllabus and they do not directly ask any.
They are two different examinations based on very similar syllabus except for a few things.
I have written both the examination, so I know that major difference is not the fact that BITSAT include English and logical reasoning.
For JEE Mains, one is set 90 questions and given 180 minutes.
For BITSAT, it is 150 questions in 180 minutes.
Observation that comes from experience:
Time is crucial.
No doubt the overall difficulty of BITSAT is less.
Time is very crucial.
If one is concentrating only on JEE and solves BITSAT paper, you probably will fall short of time. The shift is about 120 seconds per questions to a question a minute.
So, actual absolute difficulty of questions: JEE>BITSAT.
Actually solving questions considering difficulty and time stress : JEE is nearly equivalent to BITSAT.
The BITSAT has a lure of 12 bonus questions- if you attempt all 150. Do not chase these questions by attempt and marking questions you don't know about.
Hope it helps.

IIT is the dream of many candidates who left behind everything to make their dream true and a little mistake and lack of proper guidance give a bitter taste to the candidate result.
Here are the few common mistakes that a candidate do during their preparation:-
1. Never underestimate NCERT e.g.; in 2016 3 questions asked from Biomolecules chapter 14 from chemistry 12th and true line is mentioned in NCERT book.
2. Never try to collect a lot of books if you want to refer only one side book because going through the different book may confuse you.
3. Try to miss less classes no matter where you are studying because may be a class which you missed.
4. Don't spend too much time on the social network.
5. Try to avoid foreign writer book such as Irodov, Resnick and Walker series because in many cases you may get confused instead of learning.
7. Never compare yourself with the weak student and be in touch with a good student.
8. Don't worry about future just go with your preparation and be ready to face anything.
9. Don't use a calculator during maths calculation because it may decrease your speed.
10. Never lose hope and believe in yourself.
I hope these highlights of common mistakes will help you to solve and score good marks.

The crux of all the major engineering entrance exam that a student prepared or is essentially the same. They all focus on concepts of physics, chemistry and maths. The difference is only in the level of difficulty.
JEE is definitely the highest and the toughest when it comes to the level of difficulty and it tests you on applying multiple concepts in a single question. In addition to that, it also tests your endurance as an engineering aspirant. If one prepared for an exam like JEE, one can be rest assured that all the parameters of your preparation are being covered as JEE is the most exhaustive among the entrance tests.
So, one does not need to prepare separately for VITEEE as your fundamental preparation is already done. What one can do additionally is:
1. Go through past year papers of VITEEE to see the level of difficulty.
2. Take times mock sets for VITEEE. This is important because, in easier entrance exams, time management becomes a matter of paramount importance as the cut-off is higher. So, you need to answer more questions with higher accuracy.
Apart from this, no additional or separate preparation is needed.