<Tr> <Th_colspan="2"> Operation Polo </Th> </Tr> <Tr> <Td_colspan="2"> The State of Hyderabad in 1909 (excluding Berar). </Td> </Tr> <Tr> <Td_colspan="2"> <Table> <Tr> <Th> Date </Th> <Td> 13--18 September 1948 </Td> </Tr> <Tr> <Th> Location </Th> <Td> Hyderabad State, (parts of South and Western India) </Td> </Tr> <Tr> <Th> Result </Th> <Td> <P> Decisive Indian victory </P> <Ul> <Li> Annexation of Hyderabad to Union of India </Li> </Ul> </Td> </Tr> </Table> </Td> </Tr> <Table> <Tr> <Th> Date </Th> <Td> 13--18 September 1948 </Td> </Tr> <Tr> <Th> Location </Th> <Td> Hyderabad State, (parts of South and Western India) </Td> </Tr> <Tr> <Th> Result </Th> <Td> <P> Decisive Indian victory </P> <Ul> <Li> Annexation of Hyderabad to Union of India </Li> </Ul> </Td> </Tr> </Table>

When did the nizam of hyderabad sign in the instrument of accession