I was in US from Feb-Jun 2006 on L1 visa. I am married. My wife was staying in India. While filing returns online, spouse SSN is mandatory information. I have following queries:

1. What will be my residency status?

2. How do I file my returns without spouse SSN?

You are a non-resident alien, and therefore can NOT file jointly with your wife nor claim her as a dependent.

This being the case, you do not NEED a SSN for her.