First of all, your question has got some things wrong. You are projecting many present day concepts into the past.
Mughals were very much Indian in the sense of the word you are using. It would only be wrong if I were to argue that India as a concept is of recent origin. But then there is another side to that argument too. Let’s just stick to your question.
I am assuming that you want are referring to an Indian Empire or Kingdom which has attacked another.
- Indian subcontinent is sufficiently large to have ensured that there was enough land, resources and people here to fight for. No King or Emperor worth his salt would have fought for the largely non-arable barren central Asia or the heavily forested SE Asia.
- Within the subcontinent each of these Kings and Emperors fought like cats. Infact one of the reasons India ended up being a colony is this lack of unity.
- A nation state is a very recent concept. People in those time did not think in terms of India as a nation. The conception of India as a nation originates from our freedom struggle.
- If you agree with 3, then I can given you a gazillion examples of Indians attacking others. Marathas fighing Hyderabad, Mysore fighting Malabar, Lodis fighting Sharqis…the list is endless. It would make the European fighting list puny.
- Again if we think of the whole subcontinent as India, then too we have examples of invasion. These mainly heppened when the point I stated in 1 was threatened in some manner. We have the Pandyas sacking Sri Lanka, Cholas attacking the Sailendras in SE Asia, Kanishka trying to attack China (atleast acc. to some versions of history), Muhammad Bin Tuglaq attacking Tibet etc.
Human history develops along the same line almost everywhere.
Equality, Division of Labour, Surplus extraction, class division, class conflict, exploitation, revolution, equality. There are so many ways each stages could turn to, but that was not your question, was it.
Hope this helps.