I have worked for a U.S. Employer on H1B visa. In Sep 2012 I moved to my home country and worked for my U.S employer from there. In Jan 2013 I took a leave of absence, so from that time I do not get any money from my U.S. employer. What residency status do I have in 2013? Am I considered a resident or non-resident alien for U.S. tax purposes in 2013?

If you weren't in the US in 2013, you are a non-resident alien

You are considered to be a non-resident alien, because you lived and worked IN India in 2013.