If you father is on tube feeding, I suppose he is still in hospital. If that is the case, the head dietitian of the respective hospital will plane specific meals with supplements if needed for tube feeding. You need not worry about that. Usually thr tube feedings are customized according to the patients blood work, how much he is able to swallow, digest etc. So those parameters would also would be taken care of at the hospital.
Next Steps
Once your father is well and discharged home. Ask the dietitian if he still has to be on some liquid diet/soft diet or can he go back to a normal solid food diet. Accordingly you can get support from an qualified dietitian with experience in hospitals.