or (used in alternatives)

या

English Usage: Would you like tea or coffee?

Hindi Usage: क्या आप चाय या कॉफी लेना चाहेंगे?

addendum (though rarely used, it refers to an addition)

अनुपूरक

English Usage: The report included an eller with additional information.

Hindi Usage: रिपोर्ट में अतिरिक्त जानकारी के साथ एक अनुपूरक शामिल था।