Remember, if the total volume is over 20L INR, you need GST registration.
Only if Business Receipts/Turnover is above 20L, right? GST and Income Tax are two separate domains. Last year my total income did exceed 20L but I smartly distributed it among 5 heads of income and income under 44ADA was lower than 20L. I showed excess as Capital Gains and Other Incomes. Hence I was free from the burden of GST.