I have drawn jig for fork lifter in IPS unit and I found lifter fork at Grab CAD which has unit in MKS,So I have difficulties to assemble them together,So is there any solution for assembly of jig and lifter fork?
Units don't matter.
If you were to mix imperial and metric parts in an assembly, they would still show at the correct size relative to each other.
1" = 25.4mm
The only thing that could/should go wrong is if someone designed a part using the wrong units. I.e if I meant to build a metric part, but used an inch part template. In that case you are kind of screwed. The "easiest" way to fix it is not really the "best" way, but a Scaling feature can be applied at the part level to increase or decrease the model size as needed.