Assuming your visa was cancelled upon departure from Qatar it means you shall be back by May 2012. Otherwise it will 2 years after visa cancellation. Sometimes employers do not cancel immediately and the visa expires automatically after 6 months; if we consider this case then you can come back by Dec 2012.
If you have a NOC from previous employer then you can comeback immediately.
Yes the BAN is still here.
Assuming your visa was cancelled upon departure from Qatar it means you shall be back by May 2012. Otherwise it will 2 years after visa cancellation. Sometimes employers do not cancel immediately and the visa expires automatically after 6 months; if we consider this case then you can come back by Dec 2012.
If you have a NOC from previous employer then you can comeback immediately.
Regards!!