I have left supraclavicular lymph nodes swolllen(1.00-1.2 cm) for more than 6 months, accompanied with immuno deficiency

Needs doctor eval: This should be evaluated by your doctor. It may or may not be necessary to take a biopsy of the node to see what is wrong, there is a long list of possible causes. At other times it is just necessary to see if the lymph node returns to normal size with time. A lot depends of any other symptoms you have and your specific medical situation.