What are the powers of LS' Leader of Opp'n, who's called 'Shadow PM'?

The Leader of Opposition in Lok Sabha is considered as a 'shadow Prime Minister' with a shadow Cabinet. She/he can take over the administration if the ruling government resigns or is defeated on the floor of the House. She/he is permitted to oppose the government and present alternative policies. She/he enjoys privileges on ceremonial occasions like escorting Speaker-elect to rostrum.