Actually, I am an indian average student with big dreams. But, i’ve got only 7, 7.2 and 6 CGPAs in first 3 years of my high school, and being in the senior year. Our grades are scaled from 0 to 10, with 3.3 as passing one. We don’t get ranks mentioned on our transcript. I wanna know wheather my CGPAs are considerable or not. Can i compensate them through SAT.
Changing names won’t matter. 
Grades are grades. Every aspect of your application has it’s own value. In other words, you can’t really “compensate” your grades through your SAT score.
It all depends. I know that in some schools in India a percentage of 76% is considered wonderful. If your school doesn’t rank, do they provide a distribution of grades? Or mean grades of all students in your class?
Most high schools provide what is known as a “school profile” so that college admissions counselors can understand the grading system. The School profile should have this information.
The main point is to find out how you fare compared to other students from YOUR high school. Trying to compare your grades to an American hs student is not meaningful.