Dont use banks who offer demat a/c - Like HDFC, ICICI, SBI etc, They are banks & just try to keep funds with them & add on service with huge brokerage..
Try Angel broking, India bulls or Sharekhan.
PM me if you are interested in cheap brokerage of 3 Paisa & 25 Paisa..
I have both ICICI and Reliance. The latter is cheaper when it comes to low nett transaction values. The site has also become a lot better now than it was when launched. All said however, ICICI handles heavy volume days far better.
I've got a kotak account, and I find it very easy to use, reasonably priced, and they've got a really good online trading program.
I'd suggest first trying your current bank..should be more hassle free.
And if you're only going to invest, then the rates don't matter much...there's hardly a difference of about .2-.5% between most brokerages anyway.
Look for ease of use/access, and customer care.
Have heard good things about kotak from a friend as well. I have accumulated multiple bank accounts over time, so wont need to open a new one anyway, no matter which one I chose. Will check out Kotak as well.