MAT
To prepare for Gk you can just read the newspaper daily and stay updated on the current affairs. You can also try to learn some new facts about history of sports like major sporting events example world cups and olympics or you can learn about architecture and Indian culture, etc. daily. You can also take the general knowledge test in yTest here: https://www.youth4work.com/onlinetalenttest/General-Knowledge-test
No gk score of mat isnt considered in percentile but many institutes take that score in consideration in the second round of the selection.