Those specs are pretty decent for 28000 PHP = 656 USD. Except for the amount of RAM.
--> That laptop meets or exceeds all AutoCad system requirements, except the RAM, which is an easy fix.
Which make/model is that?
You should be able to add 4GB of RAM for ~$25 to get to a total of 6GB.
AutoCad system requirements: http://usa.autodesk.com/autocad/system-requirements/
The most demanding requirement is the one for 3D modeling.
It's 4GB RAM requirement is the only one that model doesn't meet.