Hi Ishitaa,
There is no set rule/figure for model accuracy, however, as long as it stays in plus minus 10%-15% window, it should be ok depending upon the industry and business nature as there are always some external factors that are not in control. If it under or over performs then you may investigate it further by clicking on the model accuracy link and see how your actual performance is vs the predicted and take necessary actions accordingly.
Hope this helps.
Regards
Nidhi