Yes, all sample packs are royalty free. They should include a EULA (End User License Agreement) document which you can reference and see if there are any limitations.
This will apply to the following products:
- JST Kaoss Volume I
- JST Kaoss Volume II
- JST Kaoss Volume III
- JST Melodic Spark
- JST Fatal Rebirth
- Riff Vault - Architects of Djent
- JST Snare Bombs
- Deathcore Soundboard
- All Drum Sample Packs