Margin used -52.90 (Does this mean I'm in profit including the brokage?)

Margin used -52.90

I know this is in profit but Is this including the brokerage?

No. Brokerage is calculated at the end of the day.

In Zerodha brokerage calculator, the brokerage is mentioned as 3.54 (below 20) - Isn’t it Rs 20 per order?

20 is the max

Brokerage at Zerodha is 0.03% or Rs. 20, whichever is lower.