Maybe you can fetch circuit limit values from full quote APIs and compare it with LTP. You can refer complete response param here.

You seem to be send the wrong query param label. It should be i. You can know more here.

We get snap quote data from the exchange and the volume data that is available is cumulative for the day until that point. You can check out full market quote APIs and WebSocket data

You can refer to the documentation here.

Yes, you can use WebSocket streaming in FULL mode.

You are sending the wrong symbol format, it should be exchange:tradingsymbol. Go through the documentation here.

You can fetch OI using quote APIs or WebSocket streaming.

https://kite.trade/docs/connect/v3/market-quotes/#retrieving-full-market-quotes

https://kite.trade/docs/connect/v3/market-quotes/#retrieving-full-market-quotes

https://kite.trade/docs/connect/v3/market-quotes/#retrieving-full-market-quotes

https://kite.trade/docs/connect/v3/market-quotes/#retrieving-full-market-quotes

https://kite.trade/docs/connect/v3/market-quotes/#retrieving-full-market-quotes

You can use the full market quote, it has timestamp field.

Can I get history of circuit limit?

The full Instrument list is used for instrument info like instrument_token, trading symbol, etc but not for live market data, so market data like last price, won't be able on full instrument list.

Do we have any api that I can use to calculate margin required for any particular trade

Yes, you can fetch up to 500 instruments in one go.

if any API provide Market Capital

Is there any method using which I can check If a stock had hit lower/upper circuit on a specific date?

In the OHLC Quote, add a field for date