ICICI 3 in 1 account is 1. Bank account 2. Dmat account 3. Trading account.
Bank account I think you have to maintain minimum of 50k average over 3 months so there are no charges.
Dmat account is for storing dematerialised shares. I think they ask for a cheque to start this account min of 500/-.
Trading account is for buying/selling shares. The more you use it the more facilities you get. I think you only get charting after 3 months of trading.
There is no minimum I know of for Dmat/Trading accounts but there is around 500/- per year maintenance charge.
New is there Speed Trader platform, but I don't know if this is additional cost.
Call them, they will send a representative to your house to explain all.
Hope this helps,
Class.