The Gitanjali group today announced the complete acquisition of Nakshatra, the premium diamond jewellery brand promoted by Diamond Trading Company (DTC), for Rs 100 crore.DTC has given the manufacturing, distribution and marketing rights to Brightest Circle - a joint venture between Gitanjali and two private companies.Gitanjali will now have the sole right of Nakshatra and 100% stake in Brightest Circle.The company plans to invest about Rs 100 crore for brand expansion and making it a lifestyle brand in the next two years.The group will soon introduce other lifestyle accessories like designer bags, belts and watches.