If I buy Bath & Basin Taps from USA , can I use in UK ?, Will the taps
fit the UK piping system.

I don't know, but if I was buying them and didn't get a satisfactory answer
from someone who did know, I'd also buy some tap connectors and a short
length of imperial pipe to go with them. You can definitely get
imperial/metric conversion stuff back here. OTOH, you might find they use BS
tap connectors anyway. Perhaps you could take some UK ones over with you to
check when you get there.

Christian.