What percentile can I expect with 21.80(4.25 - 7.55 - 10 and 10 in GK)marks in XAT? If it's above 80, can I apply to GIM or should I refrain from it?

yes, 21 should be anywhere between 80-85 and worst case would be 80 i think. Check prev yes cutoffs for GIM and then take a call on whether to apply for it.

GIM, TAPMI, IMT, GLIM, FORE, IRMA, MICA dont have any sectional cutoff

Also, do they have a sectional cut off? I have doubts over my VARC cut-off as it may be on the borderline.