As salaamu alaikum,
Giving da'wah to a Hindu is perhaps the hardest thing to do, and in other ways, the easiest. At least myself, before I became Muslim, was a challenge for my Muslims friends since Hindus generally have a strong bias against Muslims (well, I should say, the ones from the East), and this has to be taken care of first. There are also little rules in terms of what is commonly believed- some Hindus are so convinced that every thing can be true, that to settle on one thing, or to bring them to agree on one thing, is not easy.
Where do I start? lol
There is a difference, I have found between open Hindus, dogmatic Hindus, cultural Hindus, and non-practising Hindus. I will speak in the context of an educated, fairly practising Hindu.
Well there's a few things.
1.The first is to know your points in history to remove any biases. Know a bit on how Hinduism developed, the Moghul rulers, the myth of forced conversion, the dissatisfaction with the caste system, the rich cuture that Muslims contributed, and PEACE.
2. As well, they place a big emphasis on character and gentleness. This often helps you carry the da'wah without offending them.
3. Learn to discuss things very logically and stop out where their thinking is incorrect.
4. Refrain from simple judgement calls, or making statements without leading them to the conclusion slowly. Remember Hindus believe everyone's religion can be valid and don't like the idea of conversion, so don't make them feel that you are pushing them.
5. It always helps to contextualize: learn some of their concepts, their terms, and way of speaking. For example, speaking of Satya, or truth, is good to establish that only one reality exists, morals are absolute not relative. The sayings of Krishna in the Gita about worshipping One God.
6. Act like you are going through the thought process with them. Start with God in general, and develop the concept to a perfect way of life.
7. Tell them where Hinduism went wrong- that avatars (incarnates) may actually have been prophets or pious men who died and they were worshipped, and that is where the wrong turn took. Then, show them how their religion cut off long ago without any evidence to confirm, so Islam is the natural continuation of the truth.
8. Don't say off the bat that Muhammad Sal Allahu 'alaihi wasallam is in the Hindu scriptures, unless you can back it up convincingly, because I have looked over it and I am not sure, and an educated Hindu may turn around and say that it proves his scriptures are true.
If I can help, lemme know insha Allah
