In Jain cosmology, the maximum lifespan in hell is 33 sāgaropama in the 7th narak.

This is not practically convertible into ordinary years, because a sāgaropama is an unimaginably vast Jain time unit. So in simple terms, it means an extremely, extremely long period of suffering.

If you want, I can also give the lifespan of all 7 hells in Jainism.