Why does nobody talk about the fees exploitation in KJ Somaiya for a BTech course? For 2022-2023, the first year BTech fee is 4 lakh. I received an offer letter but I am not sure if it's worth it.

Every institute has the freedom to set its own fees for the various courses it offers in accordance with the rules of the state/country in which it is located. It cannot be labeled exploitation as long as it is within the specified limitations.

Remember that it is a deemed private university (Somaiya Vidyavihar University) and receives no government money. There could be several reasons why they arrived at the figure of 4 lakhs for 1st year B. Tech, as you said. You are under no obligation to participate in the course for whatever reasons you believe are valid.

What you make of it determines its worth. If you do not believe it is worthwhile, you are free to join any other worthy institute of your choice.