IIT

Cannot say surely about minimum marks. For IIT Kharagpur, minimum 45% or above marks is required in JEE.

Yes, in order to appear for JEE Mains you need to complete HSC education.

Yes, you can. IITs don't have any interest in the college you opted for UG. They only consider your GATE score.

Please check the college closing rank by JoSAA for IITs and NITs and compare with your rank:
http://josaa.nic.in/Result2016/result/OpeningClosingRank.aspx

Hi Abha,
With a score of 90% in CAT, chances for admission into FMS, Delhi look quite slim. You can always give another attempt at CAT and try to score in excess of 99% for OBC category.

If you're a General category student, you need 75% marks aggregate in 4 subjects (PCM + language) in your 10+2 examination or be in the top 20 percentile if your board, whichever is lower, to be eligible for admission in IITs. For SC/ST students, the criteria is 65% marks.

Hi there, if you are getting a rank within 6000 in JEE Advanced, I'd suggest you to go for one of the old IITs, in whatever branch you get, because they offer much greater chances of all round development than other colleges. Though, if you are too inclined for a particular branch, do take it. Don't be mad about CSE, as the branch is not what you think it is. Coding can be pursued even in other branches, CSE doesn't really matter. There are always non-core placements in coding or analytics profiles in all branches. Most companies open for all branches. So prefer old IITs/NITs if you get them.

First of all, I want to congratulate them.
266 is a very good score in JEE. I think she will get a rank under 500. And with this rank, she will get top 5 IITs. And your son will get a rank under 4500. With this rank, he will get new IITs very easily.

There are many coaching institutes mainly in Kota, Delhi amd other big cities .
Bansal classes, Allen institute, Fitjee, Career point, Resonance; these are some top coaching institutes you can join.
And more than institute your hard work will determine if you crack the exam or not.
Good luck.