Answer:
Sahil told Radhika that he had invited four of his friends for dinner that day.
Then Radhika said she will also invite her friends, which Sahil thought would be a great idea.
When Radhika asked what they should have for dinner, Sahil replied they should decide the menu then.
Step-by-step explanation:
The given conversation is in the direct speech, meaning it is a real conversation with the speakers and the speeches in their respective names. But if we are to change it into the indirect or reported speech form, we have to change some aspects of the speeches. One is to remove the speech or direct format and write it in the reported form, and also some words such as "today" will be changed to "that day" and "now" will be changed to "then", etc.
Therefore, the given conversation in the reported form will be-
Sahil told Radhika that he had invited four of his friends for dinner that day.
Then Radhika said she will also invite her friends, which Sahil thought would be a great idea.
When Radhika asked what they should have for dinner, Sahil replied they should decide the menu then.