Hello Sanjay!
For Bsc physics you must complete your 10+2 from a good educational board in science stream .
Physics chemistry mathematics/biology English  are compulsory. The admission process for Bsc physics is totally merit based. Most of. The colleges provide direct admission to the candidates on the basis of marks obtained on 10+2 . Which is determined by the cut off list generated by each college. However some Universities might conduct an entrance test for admissions to Bsc where they would be testing your skills on physics chemistry mathematics English and logical reasoning. There are also other Universities who provide long distance learning.
Hope this helps.

Your question is not clear. In India, there are many colleges for undergraduate degree in B.Sc physics.
Some colleges have their own entrace exam, some colleges take admission on the basis of the board result.
Minimum 50% marks in 10+2 or equivalent is the minimum eligibility criteria.
For the entrance exam, first the candidate has to fill the exam form from that college website.
Then the merit list is provided by the college, and the admission goes according to the merit list..