DNA: Why did Britain give 100 tons of gold to India?

Reserve Bank of India i.e. RBI has recalled 100 tonnes i.e. 1 lakh kg of gold from Britain. This is the first time since 1991 that such a large amount of gold has returned home. Has India bought this gold? And why has such a large quantity of gold been brought to India from Britain? The gold which has been brought from Britain to India is India's gold only. Big banks of all countries keep gold in banks of different countries to reduce risk.