For choices:
* या (ya) - This is the most common and general translation of "or" when presenting choices.
* अथवा (athva) - This is a more formal or literary translation of "or".
For alternatives:
* या (ya) - This can also be used for alternatives, but often with a slight emphasis on the option following it.
* या फिर (ya fir) - This literally means "or then" and is used to emphasize the alternative.
For expressing a doubt:
* या (ya) - This can be used to express doubt, like "I don't know if it's this or that."
Here are some examples:
* क्या तुम चाय या कॉफी पीना चाहोगे? (Kya tum chai ya coffee peena chahoge?) - Do you want to drink tea or coffee?
* तुम इस किताब को पढ़ सकते हो अथवा तुम फिल्म देख सकते हो। (Tum is kitab ko padh sakte ho athva tum film dekh sakte ho.) - You can read this book or you can watch a movie.
* यह काला या सफ़ेद है। (Yeh kaala ya safed hai.) - It is black or white.
* मुझे पता नहीं यह सच है या झूठ। (Mujhe pata nahin yeh sach hai ya jhoot.) - I don't know if this is true or false.
The best translation will depend on the specific sentence and the intended meaning.