Hello!

I'm 1st year now taking Masters in I.T. I need some advice on what topic should I go for my thesis.

Hope you guys can help me.

I.T. in itself is a big subject. What are you interested in?

I am most interested in web application programming but don't know what exactly to study during my thesis time.

If I was in your position I'd be asking for advice from lecturers/tutors that you can talk to directly. They should know your background to an extent, you can talk face-to-face about your research interests, and they should be able to advise you well.