Capital gain on sale of residential property used for commercial purpose

Residential property which was owned by individual for more than 15 years and used for commercial purpose in proprietary concern now sold in F.Y.2015-2016. Depreciation has been claimed on this property in business through out these years. My question is whether sale of property will be LTCG or STCG? Is there an possible way to save tax in this case? Please give reference of sections, case laws etc.