Check this link for deposits to become an alpha member. If you want to be trading both Equity and F&O, that is 20+25lks of deposits = Rs 45 lks.
Membership fees is 5lks one time, annual subscription of 50k/year for equity, and minimum transaction charges of Rs 1lk for equity F&O and Rs 50k for currency that has to be paid upfront every year. Your CA cost and everything else to start off will be another additional Rs 2lks atleast.
To be live on the exchange, you will need a trading platform and a backoffice platform. If you are happy with the NOW trading platform, exchange gives you free of cost. But the backoffice platform to process trades, maintain ledger etc will cost you a couple of lakhs a year atleast. You might need to also hire a person to do this which will be additional.
As a member on the exchange, you must adhere to all compliance. So quarterly reporting and etc. A CA can do this, buy you can say maybe Rs 1lk per year on that.
For trading F&O, you will need a clearing member. His charges for an individual might be slightly higher than what we can offer you as a broker due to our increased volume.
If you decide to move from NOW to any other trading platform, that would require you to have your own instance of OMS, frontend, data center, leased line costs etc. Upwards of Rs 12lks per year.
Assuming you stick to NOW, I’d say running cost of atleast Rs 4 to Rs 5 lks per year in addition to the deposit. This is just being member on NSE. So unless someone is paying a lot more than this as brokerage per year, it wouldn’t make any sense I am guessing.