Outstanding tax demand - but no mail received

Hello,

I had logged into my Income tax account in https://incometaxindiaefiling.gov.in.  while checking few things, I found there is outstanding tax demand for AY 2009-10 & 2011-12.  I did not receive any communication about this and I just found it.  My questions are:

1. How can I get details about these Demand notes?

2. If I am epaying this amount, Do I use Challan 280? If so which type of payment I need to select from the following:

Thank You