Consult any ayurveda physician you wl get benefit definitely avoid self medication.  There are  two possibilities problem in lumbar disc or hip joint or neck femur . So consult immediately to avoid more serious problems

You have not given full history of your father's ailment Can try hot fomentation after massage with Mahanarayan tailam. Better to consult if no response in 2-3 days.

Consult me or any ayurved doctor

Massage with  Narayan taila. Followed by fomentation. Try this for 1 week. Make sure he is not constipated.....

This looks as if your father has IVDP with mild stiffness so as early you take medicine it cures easily

Need more history Apply pain oil at night Change the sleeping posture For this consult on app

Whether pain radiates down Whether patient is diabetic and hypertensive Any other symptoms Let me know

Find out root cause of your problem by ayurved way diagnosis Correct it by ayurved way medicine diet and lifestyle corrections Finding out root cause and its cure is very important for improvement or permanent cure naturally Correct diagnosis by ayurved way is very important main factor in treatment Take any ayurved medicine after proper ayurved way diagnosis only for avoiding bad effects of intake Take online consultation directly for accurate diagnosis and treatment diet chart home remedies

Please tell him to not sleep on the right side.. Before going to sleep, 5 times breathing exercise to be practiced..