Tally ERP 9 offers a range of keyboard shortcuts to make it very user friendly.
The shortcut keys appear in button names in the button bar (right side of the Tally screen). You can either click the button from the button bar or press the relevant function key or character underlined/double-underlined.
The buttons have a function key before the button names ( Eg: F1: Select Cmp) which means you need to press F1 key (Function Key) to select the 'Select Company' screen