You are curious what Exinda OS version is required to install and use SSL certificates.
The SSL certificate should be compatible with version EXOS 6.4.0 and above.
Exinda by default offers a self-generated SSL Certificate but that is not trusted within the network. Due to security policies, you can install your own SSL certificate using the Certificate Authority of your choice. Refer to this article Uploading a Custom SSL Certificate or PrivateKey for more details.