My fingerprints can't be read due to skin problem since few years.will it create problem for me before attending cat exam

Can none of your fingerprints could be read?
This would be a problem before you attend the CAT exam because verification through finger prints is an essential step.
You need to do one thing is write a mail to the official CAT id which will be released next year for CAT'18 stating your problem with a valid proof. And then you can wait for them to revert for an alternative solution. Other than that it won't be possible for you to appear in not only CAT but other MBA exams also.
You can also ask your doctor what you can do for your unique justification in this case when you can't give a fingerprint. It's necessary to consult doctor and find an alternative solution because it can turn out to be a life time problem.
All the best. And also inform me whenever you are able to find an alternative solution. Don't lose hope. Work hard and you will get some way to reach you goal.