What happens if a buy MIS order is completed after 3.20 and the person doesn't have sufficient balance in his account?

Is the balance shown as negative and the trader has an option to pay the next working day? Does it depend whether the share in question is having potential loss less than the margin available? Or are the shares compulsarily sold off in the auction?

@Not_Intrepid : As per T PLUS 2 if you purchase share , broker require funds on third WORKING day . if share purchased today on Thursday , you can pay to broker by 10 am of Monday as per t plus 2 .