Venkata,
For the latest updates, you can always review the SAP Product Availability Matrix.
NW 7.31 is currently the highest NetWeaver relase that SAP Public Budget Formulation product is supported (depending on which version of PBF). Currently there are no plans to have PBF extended past NW 7.31.
The new product, once released, will support NW 7.4 and will become the product line for future NW releases.
Cheers,
Bret Strobo