Buying a smallcase is exactly like buying stocks, with the added ease of tracking & managing it as a separate portfolio

The Zerodha charges will be applicable over and above the smallcase charges - same as buying and selling single stocks on Kite.

Brokerage Charges: ₹0 (if you don't buy/sell a stock on the same day)
Exchange Turnover Fees: 0.00325% of the traded value
GST: 18% of brokerage & exchange turnover fees
Securities Transaction Tax: 0.1% of the traded value
Stamp Duty: 0.01% (varies with state)
SEBI Charges: 0.0002%
Demat charges per stock (irrespective of quantity/shares sold on one day) when you sell