Most Indian pet-care advice is written about heat. Chandigarh needs both halves: shade and water through the summer, and genuine warmth through January.
Bedding off the floor
This is the single most useful winter change. Cold radiates up from tile and stone all night. A raised bed, or simply a thick mat rather than a thin one, makes more difference than a coat does.
Who needs a coat and who does not
Short-coated breeds, small breeds, seniors and puppies genuinely benefit. Thick-coated breeds do not, and overheating one in a coat is its own problem. If in doubt, watch the animal rather than the thermometer.
Food
Slightly more through the cold months, adjusted back in spring. Weigh rather than guess - winter weight that never comes off is a common pattern.
Skin
Over-bathing in winter dries the skin out. Brush more and wash less, and when you do wash, dry the animal fully before it settles for the night.
Older animals
Cold mornings are hard on arthritic joints. If an older dog is slow to get up in January, that is worth a vet conversation rather than acceptance.