Finance Minister Arun Jaitley announced that India's biggest tax reform in decades, the national Goods and Services Tax or GST, will be launched at midnight on June 30. Mr Jaitley said President Pranab Mukherjee , Prime Minister Narendra Modi and two of his predecessors will be on stage in the central hall of parliament for the launch. PM Modi will deliver a speech at the special gathering of parliamentarians. All Chief Ministers will be invited for the inauguration, said Mr Jaitley.