Hi Jaydeep,
Yes you can achieve this through Adobe LiveCycle Designer Tool.
First you should download it from (Download Center) in (Application and user management) Work Center.
Install LiveCycle Designer.
Download purchase order template from Form Template Maintenance under Application And User Management Work Center.
Once purchase order template is download open it through ALD and by ALD(Adobe liveCycle Designer ) you can add a page for your terms and condition. and this terms and condition page will come along with every purchase order.
Thanks,
Manoj Kannaujiya.