1 ton will do so as 1.5ton will do even better if room is sunfacing/ top floor(roof heat issue) or you prefer chilled room...
1.5ton will be good enough and considering price to performance....its good enough as basic inverter unit....amps purely depends on ambient also mind it...
looking at heatwave in khi and outdoor temps...dont expect it to chill room while doing 2amp run....no it wont.....
any unit dropping to lower amps or fixed amps will NOT cool down as much as on its full capacity pls bear in mind..its just abt dropping how quickly to lower temps and how well your room remains cool... depends on your target set temps vs ambient diff....there are so many equations to it....it varies from day to day ...
there are many factors involved beside just unit dropping amps....