In last que i asked about 4th gen test after106day post pep/136post exposure,that was negative, but after two days i feel lymph node in neck area,that feel only by pressing not visible, is this ars ? if its ars then why 4th gen test couldn't pick it?

The test result is far more accurate than symptoms in judging possible HIV infection, and anyway ARS never causes only a single node to be enlarged or inflamed. And it sounds like you probably do not have an abnormal node anyway: this is too subtle to be significant or important. Self examination of lymph nodes is never a good idea and always unreliable. Stop trying and believe your test result.