The minimum you have, the more you gain. Anything more than 1 paisa is not good for day trading.
Do not go with these broking firms offering less brokerages. They are all their tactics. Choose anyone who provides fixed brokerage per month or 'per order' cost instead of 'per lot'.
There are discount brokers who are charging Rs 20 per order irrespective of quantity bought or sold. I recommend following two.
1. RKSV Securities (rksv.in)
2. ZERODHA (zerodha.com)
IF you need help in opening a trading account with RKSV, Let me know. you will be offered further discount if i refer you.
i think zerodha is better