There's a flat fee of Rs. 20/stock applicable when you transact in smallcases - this includes, buy, invest more, manage, rebalance, SIP, partial exit and whole exit orders. There are no charges for simply viewing or watchlisting smallcases; you are only charged when you transact.
There will be no additional brokerage charged other than this.
Demat charges & taxes incurred while buying/selling stocks will be separate; this will be reflected on your Contract Note and Ledger.