Tax On Jaggery Products

Dear Sir,

We are the in the trading business, we are buying unpacked Jaggery cube and repacking in our brand pouch and sailing it @ 5% Tax whether it's correct?

if we sales it 30 kgs box then gst is not applicable?

if we sales it unpacked only with any brand then gst is applicable for 18 kgs box?

please help Or suggest whom should we concern.