Unable to decrypt in java

[agsha]

What is the Cipher transformation string to be used while decrypting RSA in java?
I assume the default for ursa is RSA_PKCS1_OAEP_PADDING but I am not able to decrypt it in java. I am using BouncyCastle.
I have tried the following and none of it works

RSA/ECB/NoPadding
RSA/ECB/OAEPPadding
RSA/ECB/OAEPWithSHA-1AndMGF1Padding
RSA/ECB/OAEPWithSHA-224AndMGF1Padding
RSA/ECB/OAEPWithSHA-256AndMGF1Padding
RSA/ECB/OAEPWithSHA-384AndMGF1Padding
RSA/ECB/OAEPWithSHA-512AndMGF1Padding
RSA/ECB/PKCS1Padding

I also tried with Mode None. It doesnt work