Similar to CON and CIP application in US, is it allowed to file a continuation application with new subject matter in EPO ?
The epo doesn't use the name continuation and the concepts are somewhat different. What you can do however:
You can file a new application claiming priority within one year of the first filing and introduce new subject matter there. The new matter will have the new priority date and the old matter will have the old priority date.
You can also file a divisional application, which is like a copy of the old application. You cannot introduce new matter, but claim different matter that was already present in the application.