Hi Harsh,
This report is very much possible in SAP R/3. Regarding performance issues, it depends on how many proejcts / POs are generated in a fiscal year. However, you can reduce the performance issues by having period or fiscal year as one of the selection criteria (mandatory) thus by executing the report for the selected period. Also avoid as far as possible using the tables BSEG / MSEG in the program
If the organisation has BI implemented, I would suggest to develop this report in BI which would be more quick in execution, also you don't have to worry about the performance issues.
Regards,
Balachandar L