I am studying third semester in VIT Vellore. Can I join the colleges or chapters in the third semester?

I think you meant clubs and chapters.
Most of the clubs and chapters start (and for some very selective ones this is their only[recruitment]) the recruitment process in 2nd semester(when DSW allows that).
Recruitment process then keeps on continuing rather sporadically,with some recruiting in third semester. I’ll say keep a track of the instagram pages of the club/chapter(s) you want to join and you’ll get to know when they are recruiting.