Available Margin

Hi Team,
I need to calculate how much quantity i can place based on my available margin.

1. May i know how can i get the margin value based on Quantity and Price ?

For example,
TradingSymbol = "BANKNIFTY2390744400CE"
Quantity = 15
Price = 388.5m

For this order, i need to know how much available margin i should maintain in Zerodha funds ?


2. May i know how can i get the available margin in my Funds ?