1. To investigate something; to look into or ask questions about something. The HR department will be seeing into complaints of unfair firing practices. We've seen into what could be causing the server malfunction. We will keep you posted when we have more information.

2. To show or escort someone into some place, especially in a formal capacity. In this usage, a noun or pronoun is used between "see" and "into." Mary, would you mind seeing our guests into the meeting room? Allow me to see Mr. Jacobs here into his room, and then I'll be right with you.