How To Remove rust from khukri without ruining mirror polish?

[Bill DeShivs]

Many of those are nickel plated. There is not much you can do with those.
How do you know your knife is not plated? A picture would help us tell what to do.
If the knife is truly only polished steel, a light scrubbing with 0000 steel wool will remove surface rust without harming the original finish. Bronze wool would be even better. Use either dry-no oil.
If the knife is nickel plated, either of these treatments will damage the nickel.

 

[SharpBits]

Thanks.

I don't live in a western country.

Normal beeswax liquid will do? Should I store the blade outside the scabbard after applying beeswax

Always store the blade outside the scabbard. Beeswax mixed with mineral oil has been used for a very long time to help prevent rust. Sheep lanolin works as well. If you can find it where you live, try some of the more modern rust preventatives.