Two major categories:
1. Triglycerides (oil) and/or
2. Free fatty acids
Examples:
1. Edible oils: canola, cashewnut, coconut, corn, palm, peanut, rapeseed, soy, sunflower, etc.
2. Non edible oils: cottonseed, jatropha, kapokseed, etc.
3. Animal fats
4. Used cooking oils
5. Palm fatty acid distillates (PFAD)
6. etc.
Any other substance that contain triglycerides and/or free fatty acids can be used as feedstock.
However, as freight cost could be a significant add-in factor to your feedstock price, choose locally available and cheapest feedstocks.
