Job switch

Hey folks, need better advice on this matter.

I am presently in cognizant working in support role at less than 4lpa package. I have web development skillset but not getting opportunity here. When asked to my manager about opportunity he says less projects presently and will let me know.

However, I am getting an opportunity from Thinkitive Technologies, more of a startup. They are saying they would take me in probation period and offering me 4.5lpa which would rise upon conversion to fulltime. It will be in Pune location.

As I am in cognizant for 1.5yr as fulltime, what decision should I make here?

And is it worthwhile to convert from my fulltime role presently to a probation period?