i can't use volte features im my Mobile the mobile network section in there volte enable option is missing . so immediately solve the issue i can't use mobile data while calling the mobile network changing 4G to 2G coverage

I'm in India but i bought my phone soudi arebia ,How to enable voLTE in my phone? My phone is GALAXY A6,Model number SM-A600F.and indian firmware not available in sammobile website pls helpme i need volte in my mobile . or pls giveme...