Mr. kapasi notices that mr. das looks "exactly like a magnified version of "

The answer is Ronny, his son.

Explanation:

In “The Interpreter from Maladies” by Jhumpa Lahiri Mr.Kapasi defines Mr.Das as a magnified version of Ronny, who is described as having flashing silver wires and wearing brightly colored clothing. Then, he describes Mr.Das as a clean-shaven man who is wearing shorts and a t-shirt. He thinks both father and son share the same carefree spirit.

it means that the hockey puck was traveling very fast.