Non-compliance of BS-III norms would also disallow owners to get pollution certification for their vehicles earlier than the prescribed 10 year scrapping age. While the predictive age for BS-III violation is close to the 10 year benchmark, the possibility of BS-IV violation at just 7.5 years could be a point of concern.

from Times of India https://timesofindia.indiatimes.com/auto/news/your-diesel-car-could-become-non-compliant-even-before-10-year-scrapping-age-heres-how/articleshow/93965256.cms