Indian would be Hindi
Pakistani would be Punjabi
I am sure everyone in this Forum knows about the River Indus. Indus is the Greek name of the river which flows through Pakistan from the northerner part of West Punjab to Sindh. Persian language has no "s" sound, also Persian language has no aspirated sounds like "dh", "th" etc. Therefore the Persians pronounced Sindh as Hind. The real name of the River Indus is Sindhu. People of Sindh have called the river Sindu. Persian called it River Hindu. The Persians started calling the language Sindhi as Hindi. Hindi means Indian.
In due course, the Persians started calling Sindh as Hindustan i.e. the land of the River Hindu (Sindhu) Eventually Hindustan became the name of India, the people became Hindus (not in the religious sense, that came later) The language they spoke became Hindi. Later on the word Hindu came to known as a person who follows the religion of India, i.e. Hinduism, in order to distinguish them from Muslims. For Persians, Hind was the country, Hindu was Indian and Hindi was the Indian language.
Urdu is hybrid of Hindi and the languages spoken by Muslims such as Persian, Turkish and Arabic. The grammar of Hindi and Urdu is identical. Everyday spoken Urdu and Hindi are identical languages. Hindi is written in Devnagri, the script of India. Muslims started to write Urdu in the modified Arabic scrip because they did not want to pollute Urdu by writing it in the kaffir script. Also, Muslims tried to get rid of many kaffir words and replace them with the words from "Islamic" languages. That's the reason, at a literary level Hindi and Urdu sound very different, but the grammar is still the same; the conjugations are identical, the adverbs and adjectives are same.
Punjabi is the native language of Indian (East) and Pakistani (West) Punjab. The strange thing is that in India Punjabi is written in Gurmukhi script but in Pakistan, Punjabi is considered an unwritten language. Therefore you don't have Punjabi literature in Pakistan but in India hundreds of Punjabi books are published. Pakistani Punjabis do not want learn to read Punjabi because it is written in a kaffir script. Jinnah wanted to banish Bengali from East Pakistan and impose Urdu. In his view, Bengali was a kaffir language because it is written in kaffir script. But luckily, this type of thinking help break up Pakistan.
Urdu is the official language of Pakistan but only about 10% of Pakistanis speak Urdu as their mother tongue. Punjabi is the most widely spoken language in the country. But Punjabi is not written. Sindhi, Baluchi and Pushto are written languages. But only Sindhi has substantial literature. Logically Sindhi should be the official language of Pakistan or Punjabi if Pakistanis get over their kaffirphobia and started learning it in the Gurmukhi script.