Depreciation under companies act, 2013

As per Companies Act, 2013 depreciation is to be calculated based on the useful life of the assets. And the existing assets are to be depreciated on the carrying amount over the remaining useful life of the assets.

My situation: How to calculate depreciation on the assets of a Company, when those assets are acquired as a result of Business Acquisition of a Partnership Firm.

What should be the useful life & carrying amount?

Any help would be appreciated :)