Yes, you can post full videos on Instagram. However, the maximum length of a video that can be posted on Instagram depends on the type of post and your account status.
For regular Instagram posts, videos can be up to 60 seconds long. For Instagram Stories, videos can be up to 15 seconds long per clip, but you can create a longer story by stringing together multiple clips. IGTV (Instagram TV) allows you to post longer videos, up to 10 minutes in length for most accounts, and up to 60 minutes for verified accounts or accounts with a large following.