Hi ganesh

The ideal Modelling quality is 90%.
However, even if you get 90% modelling quality you can't be sure that the results are real. You must forward test the EA.

I had some EAs which earned millions in one month of backtest but on forward testing they failed after few weeks.

PS - I hope it is not a scalping EA because the brokers wouldn't allow you to use such an EA under normal conditions. They will increase the spread or give you lots of requotes.

I hope this helps.