Hi @Ankush1,
This is more of a database administration question than an OJS question; I’d suggest working just with your database tools (e.g. phpMyAdmin or the MySQL client) to get your character encodings consistent with your new and old databases, and only then introducing OJS (and its configuration file) into the mix. You might find guidance about this on StackOverflow.com. I suspect your old and new databases were created with different default character sets.
Regards,
Alec Smecher
Public Knowledge Project Team