If an NPC or perhaps a player character finds themselves inside of the ring, it could be a valid question. After all, let’s say an NPC character named Barbarian Bob wore this ring while battling a monster and died to it, and his soul hasn’t left the ring. Decades pass before someone picks the ring up again, and Bob’s soul is still inside. In this case, since souls are technically not alive, Bob’s soul remains the same as it was on the day of his death. Now for a PC, such as Randolph the Rogue, if he dies and goes into the ring, time freezes for him as well. For example, he could be 33 when his soul goes into the ring. If it takes 2 years for the party to find the ability to get him back into a body, then he is still 33 when he gets out. It’s a bit complicated and might require some DM homebrewing and intervention, but for most people time freezes in the ring.