IIM Bangalore has been patched with only one site for MOOCs which is edX and if you wish to pursue MOOCs through IIM Bangalore, you don't need any registration.
All you have to do is create an account or you can also sign up via Google, or Facebook account. Once you get registered, you can search for the university/institution with the course you are interested in.
On edX, IIM Bangalore offers 5 programs. Along with this they also offer 45 courses. Some of these courses are free, however you have to pay a small fee to get the course completion certificate.