If your GST was canceled by the department, you can apply for revocation within 90 days by filing all pending returns and clearing dues including penalties and interest.
If 90 days have passed, apply for a new GST registration.
For detailed, personalized advice, consider a phone consultancy. Hope you find the information helpful. You are free to contact me for further discussion. If you could spare two minutes of your time to write a review, it would be greatly appreciated and bring immense happiness to read it. Thank you. Shubham Goyal.