Common squirrels seen in India, probably Indian palm squirrels; seem to have drastic different behaviour. And all squirrels of a definite locality, behave in a very consistently same whay. That seems like My drastic experiences at 3 localities were as follows.
On West Bengal (Howrah, Hooghly and Burdwan District): Squirrels seem to be incredibly timid. They always maintain a safe distance from human being. They sometimes consume human food leftover, or respond to cater; but the feeder person needs to be go away from the spot. They are also quite a bit picky eater, among human remains they mainly depend on paddy, some of them don't even touch grounnuts.
On Uttarpradesh Tourist spots, particularly Agra and Delhi, squirrels come too close to the tourists. Sometimes they take food directly from human hand. Some of them even follow the tourist population for foods. Some of these squirrels are very aggressive, however they are somewhat vulnerable because people easily touch them. They aren't very picky eaters, rather they are sort of gluttony... eats whatever the tourists feed them.
On Uttarakhand state, on many places (including the non-tourist) the squirrels come very closer to human being. Not always for food, but they just come too close to human being. They aren't aggressive. They aren't very picky eaters. Though some are little bit timid; some are super easy to touch. They are super vulnerable.
I'm really surprised how the behaviour of these 3-striped squirrels vary throughout India and is consistent with locality. Learnt behaviour from parent/ peer squirrels? Epigenetic imprints? Genetic variability? Scarcity of foods? Its super surprising.