Koskikeskus is the main shopping centre in central Tampere, on Aleksanterinkatu adjacent to Sokos Hotel Ilves. It houses standard Finnish chain stores (Zara, H&M, Finnish department stores) and is primarily of interest as a practical convenience rather than a destination. The location next to the rapids and the river hotel is good.
If you want Finnish design goods, the Finlayson area shops and the city centre standalone boutiques are better options than the chains here. Worth noting as a reference point: Aleksanterinkatu runs parallel to and one block south of Hämeenkatu, giving an alternative walking route through the centre.