Than to configure the ssl I took the following steps:
In WAS admin console: Services->Policy Sets->Application Policy Sets. Than I selected WSHTTPS default. copied it and rename it to WS SSL Policy, I dint chnage anything in it.
Next, I went to Security->SSl ceritificate and key management ->Key stores and certificates I created ServerKeyStore with a self signed certificate and ServerTrustStore with the client public key
Than, I went to Security->SSl ceritificate and key management -> SSL Configurations and I created a new configuration WS SSL conf set the trust store as ServerTrustStore and Keystore as ServerKeyStore
Next, I went to QOP setting of WS SSL conf. There I set client authentication as required , protocol as ssl and rest all default.
Than, I went to Services->Policy Sets->General provider policy set bindings. Than I selected WSHTTPS default. copied it and rename it to WS SSL Binding. seleced it. than selected SSL transport and selected WS SSL conf as SSL settings
Finally I went to Services->Service providers. selected AddNumbers service and apllied WS SSL Policy as policy set and WS SSL Binding as Binding.