Explanation:

Direct speech describes when something is being repeated exactly as it was – usually in between a pair of inverted commas.Indirect speech will still share the same information – but instead of expressing someone's comments or speech by directly repeating them, it involves reporting or describing what was said.So here, the direct speech is:

Mrs. Gupta said to me, "Why are these boys standing in the sun?"

The sentence is in present continous form so the indirect sentence would be:

Mrs. Gupta said to me that why those boys are standing in the sun.