It is not clear which exam you are talking about. You have mentioned engineering as a tag. Anyways, group total is often used in deciding 11th-12th marks. It is the marks of your three main subjects for both the classes, 11th and 12th. Suppose you have Physics, Chemistry and Maths in your 10+2, then group total is your total marks of 11th and 12th in Physics, Chemistry and Maths.

Hope you got the answer to your question.

Regards.

Hey chandra!  Thanks for asking us. 

Group total means total marks you have scored of the main subjects you have taken in your +2 like Maths physics chemistry for PCM students. 

You have really scored a good group total. 

Hope you  get a bright future. 

Thank you.