Tamron 90mm f/2.8 or Tokina 100mm f/2.8?

Want to buy my first macro lens for D5100.nikkor lens is way above my budget.heard tamron gives nice shots but the build of tokina is very solid with the same DOF and bokeh. I will be also in potrait with these lens, so AF works in which lens better? I'm more serious on macro and will be on manual so AF factor not a big deal. Please suggest the cost of the lens in indian market.
Regards,
Argha Basu.

Tokina is said to be better made.

Tokina glass is way much better than Tamron glass. Tokina is under Hoya which also owns Pentax. Tamron,… Well is Tamron.

Instead of cashing out the money on another lens, have you had a look at a thing called "extension tubes", they basically make your existing lens into a macro lens.

If you are going to do portraits, neither will do a great job unless you are standing on the other side of the room. They are simply too narrow on a cropped frame camera (the D5100 has a focal length multiplier of 1.5, therefore a 90mm lens will act like a 135mm on a full frame camera. A 100mm will act like a 150 on a full frame)

In any case, I suggest the Tokina over the Tamron for the simple reason that tokina lenses are built better and that they are better quality lenses.

if you wish to do portraits, you would have to go down to a 50mm or 60mm macro lens

I was faced with the same choice a few years ago. I went for the tokina because the build quality is so much better and it was slightly cheaper. In your case I would advice you to get the tamron because that does autofocus on your camera, the tokina does not. A motorized tamron will also be easier to sell should you decide to upgrade.
Both lenses are optically very, very good
Extension tubes is a nice idea in theory but the automatic tubes you would need are rather expensive.