I�d like to know whether I could choose three from these images. If yes then which three. If no critique please.
Thanks.

http://www.bdspn.com/Istockphoto/Candle.html

http://www.bdspn.com/Istockphoto/StrawberryLeaf.html

http://www.bdspn.com/Istockphoto/GroundTurmeric.html

http://www.bdspn.com/Istockphoto/girl.html

http://www.bdspn.com/Istockphoto/girl2.html

http://www.bdspn.com/Istockphoto/Momordica.html

http://www.bdspn.com/Istockphoto/OldMan.html

http://www.bdspn.com/Istockphoto/OldMan2.html

http://www.bdspn.com/Istockphoto/Sari.html

http://www.bdspn.com/Istockphoto/ShakingHand.html

http://www.bdspn.com/Istockphoto/TwoSpices.html

http://www.bdspn.com/Istockphoto/Soap.html

http://www.bdspn.com/Istockphoto/Cowskin.html

Forget all of them, maybe, just maybe the the hand shake could make it IF properly focused - it's just too soft and not enough depth of field.

Just because you can shoot f2.8 at 100mm focal length doesn't mean that you HAVE to!!!

Depth of field can be a tool but don't just always do it.

In the portraits the focus isn't on the eyes but rather the hairs from the man's nostril 

The isolated shots will not get you into iStock! You need to be more creative.

Just shooting objects over white does not require a lot of creativity.

iStock wants to see that you can produce highly commercial images that will sell (a lot).

It appears that you are located in India or in that region - forgive me if I'm wrong. Still, you have access to plenty of opportunities in that culture that will fit into a niche in western countries so I'd focus on that.

Depending on what you prefer to shoot though.

I agree.
The worst problem is the lack of resolution. There is noise and the pictures lack sharpness and impact.
Downsizing might help.
You definately need to get rid of blur and it is true, why choose  shallow dof?

People Images were shot under low natural light. That's why .