This is a temporomandibular joint disorder. It is caused mainly due to improper alignment of the teeth, or due to trauma (injury), or due to grinding of teeth. There are various other reasons for this problem. You need to go to a maxillofacioal surgeon to diagnose the cause of the problem. also, if required, you have to undergo orthodontic treatment. The cost of the treatment will depoent upon the cause of the problem, as different causes have different management methods. If it is due to misaligned teeth, it will cost around 30k-40k for the orthodontic treatment; if it is due to trauma, it will require surgery, which can be anywhere between 5k-50k (depending on the procedure required for the surgery). If it is due to grinding of teeth, it will cost around 5k. So I'm saying that first we need to diagnose the exact cause for the treatment, only then a correct treatment cost can be known. And as for the CGHS, I don't know whether it is applicable for dental problems. I think you will be eligible if you require surgery, but it is better to enquire in a government hospital.
Next Steps
Consult a Maxillofacial Surgeon
Health Tips
In the meantime, you can apply ice packs over the joint to relieve the pain. Also, you can do physical therapy to alleviate the pain.