From Wiktionary, the free dictionary
तस्स
- Devanagari script form of tassa, which is genitive/dative singular masculine/neuter of त (ta, “that”)
तस्स
- (demonstrative) Devanagari script form of tassa (“to him, to it, to that”), which is dative singular of त (ta, “he, it”)
- (demonstrative) Devanagari script form of tassa (“his, its, of that”), which is genitive singular of त (ta, “he, it”)