Dear candidate...... hope you're doing good..

Well, securing 20k rank in JEE ADVANCED may not be enough for getting admission into any of the IITs across India. But still you can give it a try at the time of counseling. You can also apply for colleges accepting JEE ADVANCED score like IISC BANGALORE, IISER MOHALI, IISER THIRUVANTHAPURAM, IISER PUNE, IIST TIRUVANTHAPURAM , IIPE VISAKAPATNAM , RGIPT BARELY, etc. 

Hope this helps you out......

Best of luck !!