To refer to a group of 5 people, you can use the following words: ^{merriam-webster.com 1 2 3}

• Five-person (hyphenated)
• Quintet
• Fivesome
• Group of 5
• Five people in the IT Department (if referring to five people amongst many others)

Note that "people" is so general that it cannot be connected with a determinate number. ^{merriam-webster.com 1}