If Zerodha is launching US stock investing through GIFT City, I’d personally expect:
Live FX rates
Conversion close to the live market rate with a transparent and minimal FX spread.
Minimum commission
Ideally similar to IBKR, with very low or zero brokerage and no unnecessary platform fees.
Proper tax reporting
Clear reports that make Indian tax filing easier, including the required details for Schedule FA and foreign income/capital gains reporting.
Same-day deposits and withdrawals
Fast transfer both ways without unnecessary delays.
Fractional shares
Support for buying fractional US stocks, so investors can start with smaller amounts.
US IPOs, options and futures
Access to US IPOs where eligible, along with options and futures, as the platform matures.
Margin account
Access to margin trading with transparent interest rates and clear risk controls, similar to established US brokers.
Simple Zerodha experience
One clean platform, transparent charges and no complicated intermediary structure.
If Zerodha can get these right, I think it could become one of the most attractive options for Indians investing in US stocks.