I scored 89percentile in jee main.What should I do

Well you have got a good percentile, why you are waiting , apply for Josaa counselling.
You can get NITs, IIITs .
The Joint Seat Allocation Authority (JoSAA) conducts JEE MAIN counselling or admission to 100 participating colleges (23 IITs, 31 NITs, 23 IIITs and 23 Other-GFTIs).JEE Main qualifierswill be eligible to register for seat allocation in NITs, IITs, IIITs and GFTIs.

• Commencement of JoSAA 2019 Registration and Choice Filling _ second week of June
• Final Date for Registration and Choice Filling _ third week of June

For more details please check https://engineering-careers360-com.cdn.ampproject.org/v/s/engineering.careers360.com/articles/josaa-counselling/amp?amp_js_v=a2&amp_gsa=1&usqp=mq331AQFCAGgAQE%3D#aoh=15580695779253&amp_ct=1558069585182&csi=1&referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s&ampshare=https%3A%2F%2Fengineering.careers360.com%2Farticles%2Fjosaa-counselling