This is a slightly older list, but you can see the list of large brands that still use .co.in for their website, solely or along with .in . 

Google, ICICI, Expedia, IRCTC, Sbi, Dominos, Indeed, PizzaHut, Nikon, BSNL, KFC, DHL, Adidas, Sony, Qualcomm, Titan, Tata, Boeing, Seimens, Visa, Citibank, Colgate, Rcom (Reliance), Britannia, NTPC, HDFCBank, PNBIndia, BankofBaroda, Crompton, UnionBankofIndia, BankofIndia, Tanishq, CentralBankofIndia , CESC, DeutscheBank, IDBIBank, PWC, NewIndia, Airbnb, DohaBank, ReadersDigest, KVB, Adecco, NovoNordisk, Webex, Craigslist, StandardCharteredTrade, Penguin, ZEISS, HUL, FederalBank, IngersollRand, Ricoh, SAIL, Koel, IBTimes, BNPParibas, DuPont, Loreal, Cargill, Garmin, Abbott, AVON, Praxair, Marubeni, ManpowerGroup, BEL, Renault, Panasonic, PepsicoIndia, Skoda-Auto, Volkswagen, Bridgestone, SuzukiMotorcycle, Heinz, Mercedes-Benz, Merck, Saint-Gobain, Datsun, Travelex, Canon, Phillips, Epson and more ...