System.setProperty("javax.net.ssl.keyStoreType", "SSLv3");There is no such keystore type. I would just remove this line.
The above code is working for single level authentication but it is showing "Handshake Exception" when Mutual authrntication is done by adding the code below:That doesn't sound right. The client truststore is used to authenticate the server. That happens during both single and mutual authentication. If it works for single authentication it should work for mutual authentication as well. More likely the problem is with the client key, the client keystore, and the server' truststore.