Hi Nidhi, 

During your MAT registration process, you might have selected some colleges, these colleges receive your scores and according to the merit list prepared by each college, if you are shortlisted, gives a call to the candidates. 

Apart from this, if you wish to apply for any other college that accepts MAT then you'll have to contact the college's admission dept. office and inquire about the dates. 

Since many colleges have a short deadline, I would suggest you contact those colleges and get to know the significant dates and procedures as soon as possible.

Hope this helps!

Please feel free to revert for any further queries. All the best!