For this particular set up, I'm thinking that you're doing meta, ortho, and para directors, which I will give that name system which this would be considered a
(m-nitrotoluene)
toluene is a benzene group with a methyl group attached to it, and the nitro group of course is set as number 1 and will be named first.
The other way to name it would be I believe 3-methyl-nitrobenze, but that doesn't even sound right in my head, hehe, but that should be the other way to name it, but the first one should be acceptable. I hope this helps, if you have any more questions about this problem, feel free to ask me :+)