some CLG say that they give admission on jee main basis even if we don't apply for thier respective entrance exam can we get admission

Yes. Most of the state level private colleges provide admission through JEE Main score/Rank.

But you will be required to apply separately for each state.
First try to score decent marks in JEE Main paper and don't think about colleges now.
After JEE Main exam, prepare a list of colleges/state where you are looking and where you can get admission.

Good luck.