You can try the Wolff-Kishner reduction using hydrazine. This should not affect the nitro without a metal present.

Another way is to reduce the ketone to alcohol and deoxygenate via radical mechanism.

The links below may be of use for further searching

http://www.organic-chemistry.org/synthesis/C1H/deoxygenations.shtm

http://www.organic-chemistry.org/namedreactions/barton-mccombie-reaction.shtm

you can reduce the ketone with organosilane and a Lewis acid. This should leave the nitro intact.

You can also try Et3SiH/BF3-Et2O for the selective reduction of ketone. I read about this reagent in EROS (example 17).

https://onlinelibrary.wiley.com/doi/10.1002/047084289X.rt226

Fry, J. L., Rahaim, R. J. and Maleczka, R. E. (2007). Triethylsilane. In Encyclopedia of Reagents for Organic Synthesis, (Ed.). doi:10.1002/9780470842898.rt226.pub2

Thank you for all your responses, I will give the wolff-kishner a crack next week!