Subhrajit made 86 off 177 deliveries and struck 11 fours during his fine knock.
Veteran Abbas Ali was unbeaten on 50 along with captain Ajay Ratra, who is batting on 35 at stumps on the penultimate day.
Earlier, resuming at the overnight score of 60 for two, Tripura added 166 runs today in 62 overs.
Off-spinner Parvez Rassol returned with best figures of three for 42 for J&K.
The inconsequential Group C match at the Gandhi Memorial Science College Ground here has been severely hit by bad weather as only 23 overs were bowled in the first two days. The opening day's play completely washed out due to relentless rain.
Brief Scores:
Tripura: 226 for five in 85 overs (Subhrajit Roy 86, Abbas Ali 50; Parvez Rassol 3/42).
