SRM is accounted as one of the finest Institutes in the India. Many of my friends are studying there in B.Tech and doing great. But the truth behind admission is good marks either in CBSE or JEE and of course good fee (I mean good).
But I think for BBA they have some cut off for the 12th Marks in commerce stream. May be you can get the admission by clearing their exam which can be on site or off-line.
You can call them by visiting their website http://www.srmuniv.ac.in/
But do it early they have a limited number of seats.