Internal orifice of branchial Fistula is located at:
Lower third of neck over anterior border of starnocleidomastoid
Floor of external auditory canal
Posterior tonsillar pillar
Anterior to tragus on the ipsilateral side
Branchial festula represents 2nd branchial cleft:

Internal orifice: Anterior aspect of posterior tonsillar pillar.
External orifice: Lower third of neck over anterior border of sternocleidomastoid.