Let me tell you buying Mutual Fund through brokrages is never a good idea because its the most costly medium of investing. But even then if are you going with them you can have a look at one of my posts by
Clicking here. I have compared reliance money with ICICI direct. ICICI direct is free if you have mutual fund investment of more than 8 Lac else Reliance Money is cheaper.
If you are new to investment in Mutual Fund probably it would help to know various channels of investment and choose the one which best suits you. You can read about the same by
clicking here.
Also can I transfer money from Joint account to online brokerage houses ?
Yes I think you can though I have never tried it myself.