While Nepal is a poor country, I find to hard to believe that the Gurkha’s would be in the mercenary business for Russia.
The Nepalese as a rule are willing to fight for anyone that pays well...
Typically they work a "circuit"... they first go try out for the British Gurkha Regiment.. if they arent selected there, they go try out for the Indian Gurkha Regiment.. if the Indian army doesnt select them, they enlist in the Nepal Army and become "Gurkhas" there.. a significant number of Nepalese also go to the French Foreign Legion either after a hitch in the Nepal Army or the Indian Army since the French pay better, offer better equipment and training, etc..etc..
Security companies actually have to be pretty careful when hiring Nepalese (Ive personally had several dozen work for me in both Iraq and Afghanistan over the years).. because all Gurkha's are not created equally.. the level of training and the level of professionalism for example you'll see in a guy that spent a hitch in the Brit army is EXTREMELY different than the quality of a Gurkha troop you'll typically get out of the Indian regiment.. which is substantially better than what you'll get out of a guy that served a hitch in the Nepalese army..
LOTS of "Gurkha" troops make their way in to the private sector and have worked both defensive/security and offensive operations all over the globe in support of wars in the middle east, asia, and Africa (I'd assume elsewhere also.. but I have personally seen them involved in these three places)... to their credit they are loyal, hard working, and dedicated troops (albeit vastly different levels of training and competency depending on where they came from) for whoever pays them... but it is not uncommon for "Gurkha's" to have worked for multiple countries other than their own (whether the french, brits, indians, USA, US or Euro paramiliary organizations like Triple Canopy, Blackwater, SOC, EODT, Control Risk, etc.. or Wagner/Russia, etc..etc..) at different times during their careers...
Another fun fact about Gurkha's.. you have to be very careful about what you say and/or ask them to do... they tend to take you very literally.. and again they are ultra loyal and dedicated...
If youre a senior guy in charge and make a passing comment around a Gurkha to the tune of "that bastard is worthless.. he needs to disappear from the earth...".... you will probably need to provide some clarity very quickly... or that bastard may indeed disappear soon lol...