ravitejakolla
I am not exactly clear on how you used to do it but you have a couple of options.
1) Create a workflow package and execute a workflow to Publish these Assets. -> Follow section "Creating a Workflow Package - Classic UI" in documentation Starting Workflows
2) Tree Activate Assets -> You can go to http://HOST:PORTetc/replication/treeactivation.html and select the path as /content/dam to Acvitate all your Assets at once.
Either of the above options may cause performance issues on your end depending on number of Assets you have so please exercise the above options carefully.
Best Regards,
Aneet