Radius of the circular garden (r) = 56 m
∴ Circumference of the circular garden (c) = 2πr
∴ Length of the wire required to put 1-round fence
= Circumference
∴ Length of wire required to put a 4-round fence = 4 x Circumference
= 4 x 352
= 1408 m
∴ Cost of wire per meter = Rs 40
∴ Total cost = length of wire required x cost of the wire
= 1408 x 40
= Rs 56320
∴ The cost to put a 4-round fence around the garden is Rs 56320.