JEE Main

Yes, you can opt for government colleges of Rajasthan.

Hello Mahesh,
Normally, every state has common entrance test for admission to engineering colleges. Hence it's only CET through which you can get admission. Similarly for admissions to NITs it's JEE Mains which is the qualifying exam.

If you have done B.Tech marine engineering from a recognized Institute then you are eligible to seek a job in merchant navy. Clearing JEE Mains is not a mandatory requirement for joining merchant navy.

Follow the link below and check out the admission criteria for different courses:
https://www.shiksha.com/university/thapar-university-patiala-3015

Hi. For IIT, NIT, IIIT and GFTI, the opening and closing rank is available at Josaa. On Josaa, you will also get the details of course and fee.

According to me, there is no difference on BE and B.Tech. I can assure you that the courses are same in both of them. Difficulty level depends on the university and on the marking scheme.
Apart from this, practicals are there in the course but college fails to provide practical knowledge. A few institutes take students for industrial visits.

Yes, if you consider getting a good decent branch.

It depends that which tuition you have joined. If you have joined a good tuition, then you don't need these things unless you go for it.

After scoring good rank in the exam, you are eligible for some top institutes of India.
Firstly, you should know your capacity, ability and patience as it plays a very important role in the exam. It can be done from anywhere until and unless you are hurry to get selected.
You can even prepare for it from home itself by watching NPTEL videos on YouTube.

JEE is a tough exam and you must work rigorous and with proper guidance for that. It is possible to crack but without proper guidance, it would be difficult. Watch YouTube videos, solve old question papers, read good books like Arihant publications, HC Verma, RD Sharma, OP Tandon, Rasik and Halliday, NCERT, etc. Pradeep is also good. Join some good rest series by brilliant tutorials and FIIT JEE. You should be polite, humble and honest. Don't be arrogant and keep motivating yourself. Good luck.