I have a E mount a6500, will the EF mount Sigma lens fit my camera if so will it crop or not?
Are you sure your Sigma lens has a Canon EF mount? What is the description of the lens?
All Sony mirrorless cameras use an E Mount. Some of these lenses are designed for APS-C sensors and some are designed for full frame sensors. The former usually have E in their description whereas the latter have EF in their description. The EF lenses still have an E mount though. An EF lens on an APS-C camera will give the same field of view as an E lens on the same camera (if it has the same focal length).
Dave