Hi Abhisurya soni, I am considering that you are in the science stream

It totally depends on your point of interest in which field you want to make your career. I am suggesting you some field and exam that is conducted for the same.

Engineering:-there are a various exam in for these fields you can give for taking admission in quality institutions 

Exams:-

JEE Mains, JEE advance(only after you qualify mains), BITSAT, VITEEE, SRMJEE.

for JEE exam pattern and other relevant information you can visit the following link:-

https://engineering.careers360.com/articles/jee-main-exam-pattern

for BITSAT you can visit below link:-

https://engineering.careers360.com/articles/bitsat

for more exam you can visit:-

https://engineering.careers360.com/exams

Medical:-for taking admission in premier colleges for medicals you can give following exams

AIIMS, AIPMT, JIPMER.

Defense:- If you want to make your career in this field you can give NDA.

https://competition.careers360.com/articles/nda-exam-pattern

you can also give direct SSB interview on the basis of your class 12th marks, for that you have to apply for 10+2 TES