"in the new time." This refers to when God restores all things. Alternate translation: "at the time when God makes all things new" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Sitting on his throne represents ruling as a king. His throne being glorious represents his rule being glorious. Alternate translation: "sits as king on his glorious throne" or "rules gloriously as king" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Here sitting on thrones refers to ruling as kings. The disciples will not be equal to Jesus who is also on a throne. They will receive authority from him. Alternate translation: "sit as kings on 12 thrones" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Here "tribes" refers to people from those tribes. Alternate translation: "the people of the 12 tribes of Israel" (See: [[rc://en/ta/man/translate/figs-metonymy]])