Hi Raunak,
OAIS is a high-level reference model, which means that most repository-like systems could be considered "compliant" at some level. While OAIS does a great job of describing what repository-like systems should off, most of the technical details are left to
the systems themselves.
So, to answer your question, I would consider DSpace "compliant" with OAIS at a high level as it has "data flows" like those defined in OAIS. However, DSpace often uses different terminology than OAIS uses, so if there's a specific data management activity
you need more information about, feel free to ask on this list and we can help point you in the right direction.
Tim