Gst registration

Dear Members,

Proprietory Concern M/s A (Textile & Readymade Garment) was having Turnover of Rs. 80 Lacs for the Financial Year 2016-17 and for Financial Year 2017-18 (Apr to June 2017) Turnover is Rs. 18 Lacs, does it need to do GST Registration based on last year ?

2) If current year Turnover Cross Rs. 20 Lacs then ? 

Please Guide.