As well as caste, Indians are also obsessed with:
Body weight. They will think it's an entirely normal conversation starter to tell someone that they've put on weight since they've last seen them.
Tea - they have to have their tea at the same times every day and must not digress from the schedule
Food - as soon as breakfast is over, it's time to start preparing for lunch, and then as soon as the lunch dishes are washed then it's dinner planning time.
Superstitions - eg wearing a black thread to protect you from people cursing you, putting a black dot behind your kids ears before going to someone's party in case someone there is jealous of your ability to reproduce and does black magic on them. If you are ready to leave the house and someone sneezes, everyone has to take their shoes off and put them back on again before being allowed to leave, otherwise a fatal demise awaits you. So many more!
Indians born in western countries are obsessed with brands, what car you drive, showing that you have money, and hiding that you sometimes shop at Aldi by hiding packaging from guests or transferring products into branded packaging.
Marriage - how old someone one is if they're not married - wondering why they're not married - asking them when they're going to get married. Linked to that, when after marriage will they have kids - "So and so have been married for 10 years but still haven't had a baby, they should stop gallivanting on holidays and get on with it"