Companies hire interns to train them and offer a full time job. However, mishaps, which might not be realised until stated by your mentor may put you in a tough situation. A few tips which should be taken care of while interning at companies:
Avoid any kind of communication gap: As an intern, it is required that the mentor should be completely aware of your project and its progress. Sometimes difficult projects might have flaws in it. These flaws should be known to the mentor.
Project Ownership: Try to be answerable for all the functionalities of the project. It is not necessary that you should have a deep knowledge of all the modules, but yes, the modules you worked on should be well understood.
Feedback: Take mentor feedbacks seriously. Every weekend ask your mentor about your flaws and how to overcome it.
Give in your best: Do not hesitate in working overnight. Try your best to complete the project and make your experience memorable.