India has received foreign direct investment (FDI) worth USD 51 billion in the last six months, reflecting sustained global confidence in the country's growth story, Amardeep Singh Bhatia, Secretary, Department for Promotion of Industry and Internal Trade (DPIIT), said on Wednesday. While speaking with media persons, he said, "As part of its startup push, DPIIT will organise National Startup Day on January 16, during which 75 Grand Challenges will be launched to foster innovation and problem-solving across sectors."