Nearly a tie: Argentina and India differ by barely -12%% in area — about 2,782,703 km² km² against 3,155,807 km² km².
Argentina sits in South America, India in Asia. On the old Mercator map the latitude gap distorted how large each felt beside the other; at true size the answer is simply 0.9×.
The old map muddied it further: Mercator inflates Argentina about 1.5× and India about 1.2×, so on a Mercator-style map this pair appears 1.1× apart instead of the true 0.9×.
India fits 0× into Argentina.