Oh God! Really sad to learn about this one where another director forged your signature.
Yes, as pointed out above, you could register an FIR since forgery is a criminal offence. As far as the procedure is concerned, go to the local police station applicable to your company.
Though it my not always be possible, Maybe, you should consider using digital signture certificates.
You can read here on MCA website or on this page on Digital Signature .
This stays on your machine and is safe. But you should not install your digital signature on another person's machine. if you need to use it on more than once machine, you can use USB Token for Digital Signature which offers portability with security.
Hope the above helps and wish that things turn out to be fine for you.