Symbian Signed is the signing program administered by the Symbian Foundation on behalf of the community. If you are writing an application to be deployed on Symbian-based phones, then you will need to know about Symbian Signed. In terms of cost if you plan to deploy your application commercially you will need a Publisher ID which costs $200 per year and each time you sign a SIS file it will cost €10 using Express Signed and €150 if you use Certified Signed. Once your application has gone through Symbian Signed you can distribute it as you choose.
Download Symbian Signing Tools Collection: FreeSigner.v1.01
SignSis 1.03
RootSiGN
SISSigner
SignSISGUI
BinPDA SignSiS
you can try online signing also.but it may not work for some application go here