Can some one check if I did it correctly as taught by Zerodha varsity?
Here is the link to my excel sheet
I think all the legs should be of same expiry. i.e you should be selecting April monthly expiry options.
Additionally, if you are trying to find arbitrage opportunities it is not really worth the hassle. In current era of arbitrage funds it is highly likely that some algorithm will find an opportunity before you find it. And in most scenarios profit after all charges is very minimal.