Hello Mr. Sanjay
In ayurvedic texts there is no reference as to dharan, but some practitioners have their own way and logic to set the things right. Basically due to inflammation of the intestines or gastritis
pulsation is felt over artery
which is regarded as dharan displaced. By manipulating they try to move the swollen part away from artery so that pulsation is felt no more and patient feels better. Some pull thumb of feet, some tie a thread and today I have read your details also. There is no set procedure in texts.