When it comes to Zero brokerage trading India, do they have any hidden charges?

There are no hidden charges with a broker like Zerodha, Angel broking, Prostocks, etc. Other charges like transaction charges, STT, SEBI turnover fees, GST, stamp duty, demat charges are extra from brokerage and you need to pay as per the broker's policy. There are no other charges charged by broker like minimum brokerage or any hidden charges.