I don't know very much about CUDALink, but I would first try updating the paclet:

http://support.wolfram.com/kb/12510

After this I would try resetting Mathematica's configuration to its installation default settings:

http://support.wolfram.com/kb/12464

And then run the command RebuildPacletData[].

If neither of these help, I would contact Wolfram Technical Support. I would email them, since they may have to look into the issue. When emailing them, include your activation key for Mathematica ( evaluate $ActivationKey to find this ) and a Mathematica notebook where you have evaluated the command

SystemInformation[]

This notebook will give them more information about your installation's configuration on the machine and may help them resolve the issue.

http://www.wolfram.com/support/contact/

Thank you very much for the reply.

I still get "False" as output for CUDAQ[].

As you suggested I would contact the Mathematica Technical Support.

Regards, Manickam