sir i want to know that what should i do now focus on apr.mains or advance 

Hello VidishCongrats for 98.25 percentile in JEE mains .According to me you should give Aprill attempt also because it will give an extra practice for JEE advanced . If you know that there will be Best Of Two from both the attempts i.e JEE january and april.This april attempt will help you to sharpen you skill and help you to increase your confidence on some topics which will also be cover in JEE advance and it will also check your weak topics which you face difficulties and later on you can work on that topics for good marks in JEE advance.I hope you get my point.Thank You and GOOD LUCK!!!