Hi,
yes, SAP_APPL 606 0000 means no SP level,
Latest SP level in EHP6 is 0007
SAP_BASIS 731 0007
SAP ABA 731 0007
SAP_BW 731 0007
SAP AP 700 0029
SAP_APPL 606 0007
For HCM , please check SAP Note 1645464,
SAP_HR 604 0062 (see note 1645464 for details)
EA_HR 606 0022 (see note 1645464 for details)
Best regards,
Praveen
(Reward point if it help 
)