Sigma 70-300mm or tamron 70-300mm for nikon d5100?

I have a nikon d5100 with kit lens 18-55mm.am
planning to purchase a new telezoom lens for it.
my budjet is low (maximum 10k).am
considering sigma and tamron 70-300mm.but
am confused between these two.TAMRON AF
70-300mm F/4-5.6 Di LD & Sigma 70 - 300mm F4-5.6 DG Macro… (with built in motor). I knw
sigma have another version of this lens with APO
( Sigma 70 - 300mm F4-5.6 APO DG Macro) but its
around 15k. So which is better sigma or tamron?
and wat's APO? Is it really matters? Design wise i like tamron.

Added (1). OR do i have to purchase a nikon 70-300mm or 55-300mm with out having an inbuilt autofocus motor? So that i will get the same image clarity of an expensive motorized telezoom lens of nikon!
But should do manual focus.

Tamron is a better choice for sure. I know of a friend who is a professional photographer and uses the same lens to take some great shots just that he owns a very basic Canon EOS 1100D.

tamron would be my choice had I been in your place, but i believe you can check it out for yourself at the store. Try shooting from both the sigma and tamron lens in broad daylight at the store. That should help you make up your mind. Afterall, you can get a million answers here but the practical experience and your opinion on the same can't be substituted in any way.

happy photography.

If you want auto focus, the lens must have an internal focusing motor. Nikon makes a 55-300 lens that does a decent job. You might explore what Nikon has before going to a 3rd party lens. Not that there's anything wrong with the Tamron or Sigma, just that you know a Nikon lens is going to fit and function like it's supposed to. Just know that there are plenty of Nikon lenses that do not have the internal focusing motor. If you don't mind focusing manually, then there are some older, very good used Nikon lenses out there.