I had got my regn letter within 2 months of getting registered. and if you haven't got it yet, I'd recommend you to go for icai once and inform them there......
Get a written application signed by them...so that there is nothing to worry in future.. Surely your problem would get resolved.
E-sahayata is also a good option. But recently when I had submitted my query , I didn't got confirmation link for submitting my query.
So it's better to finish it by going once to institute rather than staying confused and in doubt.
Good luck for may 13 :)