Indian investors and markets will keep a close watch on Tata Consultancy Services’ Q2 results as the earnings season kicks off, while the much-anticipated 57th GST Council meeting begins tomorrow, with changes to the registration, returns and refunds mechanisms on the agenda. However, US markets tumbled on Wednesday as higher oil prices, amid Iran’s plans to close transit routes in the Strait of Hormuz that it considers illegal, pushed US Treasury yields to levels not seen in more than two decades.