DescriptionLet $F$ be a one variable function field over a complete discretely valued field with residue field $k$. Let $n$ be a positive integer, coprime to the characteristic of $k$. Given a finite subgroup $B$ in the $n$-torsion part of the Brauer group ${}_{n}br(F)$, we define the index of $B$ to be the minimum of the degrees of field extensions which split all elements in $B$. In this thesis, we improve an upper bound for the index of $B$, given by Parimala-Suresh, in terms of arithmetic invariants of $k$ and $k(t)$. As a simple application of our result, given a quadratic form $q/F$, where $F$ is a function field in one variable over an $m$-local field, we provide an upper-bound to the minimum of degrees of field extensions $L/F$ so that the Witt index of $q otimes L$ becomes the largest possible.