Include Gst in magento2

There are premade extension available for Indian Sub-Continent.

you need to create 2 types as CGST and SGST for within states and IGST for all over india. please go through below link for more details

https://magecomp.com/blog/create-indian-gst-tax-rule-magento-2/

https://meetanshi.com/magento-2-indian-gst.html

Reference : Stack Exchange

You can simply setup GST tax rates, rules and class in Magento 2. You don't need any extension for this.

Download your required tax rates csv file from here and import in your Magento 2. https://github.com/amansrivastava/magento2-in-gst-taxrates/
You need to keep in mind Magento 2 latest version has states list in directory but earlier versions were not having this. So if your Magento instance doesn't show indian states list while checkout. First install this module https://github.com/CreDevLab/magento2-directory-indian-states

• Then import tax rates and create 4 tax classes: GST 5, GST 12, GST 18 and GST 28
• Create Tax rules, here keep in mind that there is different GST treatment for interstate sale and intrastate sale. So you'll need to create CGST, SGST and IGST tax rules and assign to respective class.
• Total 12 tax rules will be created.
• Assign tax rates to respective tax rule and you are done.
• Assign these classes in the respective product and you are ready to sale with GST pricing.

I have added all steps in blog post so that everyone can get help from it without buying any paid extension. http://www.credevator.com/how-to-configure-gst-in-magento-2/

[Update]
I have added above steps in a module which can be directly downloaded to your magento instance and you tax rates will be configured on a button click.
https://github.com/Magento-Garage/m2-gst-india