Options trading

I’m new to options i understand the puts and calls but when i was checking order placement buy call its say quantity 75 is these one lot size or we can can change the lot size

Lot size can not be charged.

You can buy in multiples of lots.

75 / 150 / 225 etc.

It is same to futures too.

If you are new to trading don’t trade in futures and options.

Lots are standardized by the stock exchange.

Options are come in LOT and Lot size is 75. You can only buy in multiple of 75.
If the option price of any segment is Rs. 10 and you want to buy 2 lots I.e. 150. So you need 1500 rupees.
I am telling about nifty options in example.