I had blood stuck on my finger when home. When on the road I get a doubt if I made my finger tahir.
When trying to recall, I remember going to the wash basin and I put drops of water to rub on my hand to remove the stuck blood. I don’t remember after, whether I put water to wash it away or not, although I feel I must have done it, but I can’t recall.

If I dried my hand with the towel after, is it najis or not? Will appreciate your guidance.

Since you are certain that the finger was najis, and you are not certain that you washed it, then it is still najis, and needs to be washed.