How to treat this matter

Sejal Golecha (49 Points)

18 October 2020  
my proprietary business turnover 30 lacks purchase, 35 lacs sale, rental income from commercial shop in my personal name 3 lacks, I am in composition scheme, at what rate i have to pay tax?
1)if same as composition then in my case 35+3=38*1%=38 k
2) new scheme of 6% tax in my case I have to pay 35+3=38*6%=2.28 lacks
so my rental income becomes almost zero
which one is correct
3) As my turnover is less than gst limit,can I cancel my gst registration?
4) After cancellation of my gst,if I received rental income then what will happen
5) any other way?