CBSE 12th

if you can take admission you should definitely take it this year because taking a drop a studying a full year the whole same thing is very difficult.
I myself is a dropper and I had a very bad experience so would recommend you to take admission this year

yes you would definitely get in nit which are in North East or are in your state

thapar university does not take jee rank but takes jee marks so it is difficult for 103 marks to get in thapar

Its all depend on ur interest. I should suggest to have choice of core branches.

try in private college . you will definitely get admission

Dear Jinet,
If you are good at the Physics and Maths then go for Engineering . and if you sound in biology then go for medical.
but choosing one is purely your decision. i would suggest you to for with your own favorite zone/subjects.so draw an conclusion now. and Start working on it.
wish you luck.