Yes, the guidelines to place K and Kn pins for QDRII/+ SRAM interface are different for ALTMEMPHY and UniPHY based IPs.
As per the guidelines in the External Memory Interface Handbook, K and Kn pins should be placed on DQS and DQSn pins of the write data group when implementing QDRII/+ SRAM interface.
Altmemphy based QDRII/+ SRAM IP required you to place K and Kn pins on DQS and DQSn pins of the write date group respectively.
QDRII/+ SRAM interface implemented with UniPHY based IP does not have this restriction. K and Kn pins can be placed on DQ pins as well as DQS and DQSn pins of the write data group. Make sure the pins are differential pin pair.