Let F be the function field of a curve over a complete discretely valued field. Let ℓ be a prime not equal to the characteristic of the residue field. Given a finite subgroup B in the ℓ torsion part of the Brauer group ℓ Br(F ), we define the index of B as the minimum of the degrees of field extensions which split all elements in B. In this manuscript, we give an upper bound for the index of any finite subgroup B in terms of arithmetic invariants of F . As a simple application of our result, given a quadratic form q/F , where F is the function field of a curve over an n-local field, we provide an upper bound to the minimum of degrees of field extensions L/F so that the Witt index of q ⊗ L becomes the largest possible.