see vanshika for ota preparation u should start ur study ryt now .and apart from ur books u can read engilsh news paper daily,by this u will be able to learn the ryt words and sentences.and ur GA will also improve.good luck
see Vanshika for OTA cut offs are around 80, and you dont need to give maths paper, improve your english section to the fullest as it fetches a hell lot of marks, aim around 55-60 in English & around 30 in GS. With this you clear OTA cut off