To make a choice between the two first you need to be sure if you are choosing between colleges or choosing between courses. I will give you a brief description of both the colleges.
KJ Somaiya
KJ Somaiya has better ranking than Welingkar and is more recognised in the corporate world. Also its flagship course Communications Marketing has wider scope in comparison to E-Business.
Welingkar Bangalore
It is situated in the IT hub of the country and has a great campus. Its flagship course of E-Business is like any other MBA with an additional inclusion of IT related subjects. These subjects aim at providing benefit to people with technical and non technical background both.
So the final choice is yours to make based on your interests.