Is my dslr compatible with my lens?

I have a d5100 is it comparable with Tamron AF 70-300mm F/4-5.6 Di LD Macro (for Nikon Digital SLR) Lens

Yes… It says it right there… Macro (for Nikon Digital SLR) Lens…

That lens will fit but it will not autofocus on the D5100 - you'll need to focus it manually.

No problem. Now if you get the version with Built in motor then it will even autofocus on the d5100