Who gave Kora and Allahabad to Marathas?

Shujāʿ al-Dawlah ceded Kora and Allahabad to the Marathas in return for their support. It was one of the conditions of the first treaty of Benaras signed in 1773.

For further reading check the following articles:

• First and Second Anglo-Mysore Wars
• NCERT Notes on Third & Fourth Anglo-Mysore Wars