Hi Pooja
From the select list you can select SP 05 (Always N-1 SP level).
1. Before that check the PAM current OS / DB supported EHP7.
2. From ECC system you having any other SAP systems are connected?(like SAP BI,PI) if it is yes, Kindly refer the SAP Note
1388258 - Version Interoperability within the SAP Business Suite
BR
SS