This isThe Hoax Or Fact site looked into a similar claim - that, for nationalistic reasons, Ratan Tata rejected a Pakistani offer to buy Tata Sumo Grande cars.
They conclude it is fake news. Please check the url I have shared below for reference.
any kind of high profile business like this between India and Pakistan is officially restricted by Government of India. Therefore, there is no question of any such trade proposal between Pakistan Government and the Indian company Tata Group.
http://www.hoaxorfact.com/India/tata-group-ratan-tata-rejects-pakistan-governments-multicrore-offer-to-buy-tata-sumo-grande.html They quote a Tata spokesman as saying:
“The news is incorrect – the company has not received any such order, and the trade between India & Pakistan, automobiles are in the restricted list. Hence, the question of Pakistan having placed any order with Tata Motors for automobiles does not arise.”