Though MAT is for 200 marks Indian and Global Environment is not considered for calculating your percentile. So the percentile is based on 160 marks. The composite score is the marks that you secured on the basis of the exam scored in the first 4 sections.Your percentage is calculated using the formula:

Your Marks/Total Marks*100

Going by that, 641.50/800*100= 80 percentage.

Going by previous years trends, you might have chance in the following colleges:

BIMTECH

IMS, Ghaziabad

New Delhi Institute of Management

Kristu Jayanti

Jaipuria Lucknow.