Zerodha calls itself a discount broker but they have a lot of hidden charges. Their brokerage charges are too much when you have to sell your shares. Instead of gaining profit you end paying half of it to them and if you are in a loss while trading you end up with a more loss with Zerodha.
If you are an existing customer, keep a close watch on your ledger balance, you will know what I am suggesting here. The Annual charges are taken in advance even before the year ends. For eg., if the annual charges are due in May they will charge you in the month of February.
I would not recommend you to join Zerodha and if you are already a Zerodha customer then be cautious.