Clarification on "taxable income" in gst annual return

Hi CAClubIndia Team,

I need one clarification while filing the GST Annual Return for FY 17-18.

Under section "4. Details of advances, inward and outward supplies made during the financial year on which tax is payable", does the item "Taxable Income" should include only those sales which are made after GST registration?

1. We registered for GST in Feb '18. Before that period (i.e. Apr '17 to Jan '18), our outward supplies (sales) were less than 20 lakhs (it was around 5.2 lakhs).

2. We have paid GST and filed monthly returns for the sales made between Feb '18 to Mar '18.

Here, we require clarification on the term "Taxable Income". In our case, should the term "Taxable Income" should only include sales figure for the month of Feb and Mar '18.

Appreciate your inputs on this subject.

Thanks & Regards,

S G Shet