If you have a jio fiber stb box with active jio fiber connection but remote control of jio 4k set top box is not working then need not worry. You can get free replacement of Jio remote if no physical damage is done. That means no scratch or backcover is lost or anything broken.
If that is the case then call 18008969999 and ask for free remote replacement. If the executive ask for any money even when no physical damage on remote then only pay via jiolink or send that executive back and again call above no and ask for free replacement again so that they can send an honest executive.
If any physical damage is done on remote then you need to pay ₹599 for new Jio stb box remote.