Please resolve my issue regarding gst ?

But income tax is the totaly different scenario u can opt 44 ad for income tax purpose

dear sir raja ji and mubarak r momin .... my question is .... since i am beliw 20 lakh limit ..... if i purchase something and then sell and make profit ... then will i also have to calculate gst on my profit . or no need to pay any taxes related to gst .

no need to pay any taxes related to GST to the government

If your supplier is registered and charge GST in your purchase bill then u have to pay that GST to your supplier only

The following points to be considered:
1. whether you want to supply to outside state or sez. if yes, you need to mandatorily register irrespective of turnover.
2. you avail services listed in sec 9 (3) or 9 (4) applies where reverse charge mechanism applies, then also you need to mandatorily register (irrespective of turnover) in order to make payment. for eg: you avail lawyer services.
3. if not covered in above points, then calculate aggregate turnover as per act to see whether your aggregate turnover is less than 20 lakhs. if less than 20 lakhs no need to register.
4. if unregistered, the gst paid on purchases is to be charged off to p&l account and you cannot take credit.
5. similarly an unregistered dealer can only give bill of supply and not tax invoice. hence you are not liable to collect or pay gst on your sales.