An individual is treated as 'Resident but Not Ordinarily Resident' (RNOR) if any of the following conditions are satisfied:
(a) an individual who has been a non-resident in India in 9 out of 10 previous financial years preceding that year, or
(b) if such individual has been in India for an aggregate period of 729 days or less in the preceding 7 years,
If you are planning to come to India on 10th of Oct 2021, your RNOR status would be valid for 3 years. i.e. till 9th October 2024.