thank you
but I can't understand the eligibility bsc physics / btech 1year???
if I will do bsc physics  only then it will be okay .

Yah for lateral entry you can go either by btech / bsc.
For btech you studied first year in one College and joining 2 nd year in another college.it is possible by leet exam.

for bsc physics
which one is best college or university?

for bsc physics
which is best a college or university?
please tell

Top colleges/university offering bsc physics are:-
Christ universityKristu Jayanti CollegeJain universityLoyala CollegeSt Xavier College Mumbai etc

I mean which will I prefer a college or a university?

will you please tell me the age limit for joining or applying for air force ??

The age limit criteria for different positions in air force is :-
.
For Airmen:

Your age should be in between 16-20 years (positions available for candidates with matriculation or below) 16-22 years (positions available for candidates with intermediate qualification)16-22 years (positions available for candidates with diploma qualification)20-25 years (positions available for graduate individuals)20-28 years (positions available for post-graduate individuals)Gender:Male/Female (Depending upon the type of job)
Nationality: Indian
Marital Status:Single.For Officer:

Your age should be in between16  to 19 years (candidates applying for NDA) Your age should be in between 19 to 23 years (for graduate individuals in flying branch)
18 to 28 years (for graduate individuals in technical branch)20 to 23 years (for graduate individuals in ground duty branches)19 to 23 years (for engineering graduates in flying branch)18 to 28 years (for engineering graduates in technical branch)20 to 25 years (for engineering graduates in ground duty branches)18 to 28 years (for post-graduate individuals in technical branch)20 to 25 years (for post-graduate individuals in ground duty branches)