Resource conflict when start a new browser-watirweb driver

I have created 6 threads and now each thread will create browser and
then each of them will test my website.

The problem I am facing that, threads gets stuck just before or in the
instruction:
@browser=Watir::Browser.new

Any such experiences?

Is there anything like resource conflict for this particular
instruction.

Interestingly, sometimes this problem hapens… and somethimes it doesnt,
may be those codes are diffrent, I change codes but dont remember
exactly I have changed code or just it depends on the OS for the
resource allocation.

Kindly tell me if any way to find out if there is any resource conflict
problem?

It would help if you could provide a bit more of the surrounding code,
and explain exactly what you mean by “stuck”.
If you’re using a specific profile for the browser then there would be a
conflict, but that command itself looks ok, unless each thread is
overwriting the previous instance variable. Are your instances of
@browser separated by multiple instances of a class?