Hi Akanksha
You may be able to get the same effect by taking a slightly different path. In a Plugin, we sometimes test for Depth if there is a danger of recursion (where an Entity creates an Entity, which triggers a Plugin to create an Entity, and so on).
Importing a record adds +1 to the Depth. So, a Contact created through the UI will have a Depth of 1, but a Contact that is imported will have a Depth of 2.
You may be able to take advantage of this to detect imported records, but you would need to take care - it is a bit of a work-around ...
Good luck!
Brad Orders
Brad