Relay replacement for my UPS - compatibility confirmation
The original says 12A for 120VAC while your replacement says 10A at 125VAC. That's a reduction in capability, which means it's not a straight drop in.

To see if the relay is used to switch 120VAC you will need to trace the circuit and see what it switches. If it switches DC then the switching part will be fine. If it only switches less than 10A it will also be fine.

Another part to worry about is the coil current. If the current needed to hold the relay closed is higher then other components will get stressed.

It is also possible that the original relay has an integrated flyback diode and the new one doesn't or the other way around. If the relay is installed such that an integrated flyback is forward biased you will short out the coil. If the flyback is missing then it will need to be added.

There are probably more things I am missing here, but you can see there are a lot of things to worry about when swapping out components for similar products.