Hi Midhun,
These types of certificates are used for Transport level authentication, hence do not require private keys.
You can import these certificates in TrustedCAs keystore view and it should work.
Please note the certificates must be CA signed and must have 3 chain certificates.
1. Root CA
2. Intermediate CA
3. Main Certificate
Ensure you install the certificates in the above mentioned sequence.
Keep us updated on the progress.
Regards,
Nitin