No GST 0 or Exempted in India GST

How will I add those details?

I did not fully understand your question. There is an option of selecting if a item or service is Non-GST.

The application I usually use has an option for GST 0. Even Saudi has an option for KSA VAT 0 in ERPNext. I need that option to integrate ERPNext with the application I use

In that case you can create your own zero rate sales/purchase/item tax and charges template.

I just decided to use the exempt option but thanks

That is the best way to do it.