Final answer:
To convert the sentence into indirect speech, the tense changes from present perfect continuous to past perfect continuous, and the preposition and expression of time are adjusted accordingly.
Step-by-step explanation:
To change Reena's direct speech into indirect speech, you need to change the tense and modify the point of view. Reena's direct statement is: "I have been living in Mumbai from last ten years." When changing this into indirect speech, it becomes: Reena said that she had been living in Mumbai for the past ten years.
The change requires moving from present perfect continuous tense (have been living) to past perfect continuous tense (had been living), and the preposition 'from' changes to 'for' to fit the past perfect continuous narrative. Also, 'last ten years' changes to 'the past ten years' to reflect the passage of time accurately.