After entering your 1099-NEC, you will encounter a screen titled "Does one of these uncommon situations apply". Check the box "This is not money earned as an employee or self employed individual; it is from sporadic activity or hobby".
The IRS considers anything on a 1099-NEC to be self employment income. TurboTax (TT) aggressively steers you in that direction, even if the amount is on a 1099-Misc. If you try reporting 1099-NEC income as anything else, you chances of hearing from the IRS are higher.
What does "internship through his college" mean? Depending on the details, there are three different ways the income should be reported:
1. If he worked for the school, it could be reported as taxable Scholarship (stipend). ColeenD3's answer link shows you how to enter. For more details, see https://ttlc.intuit.com/community/tax-credits-deductions/discussion/re-1099-nec-graduate-student/01/...
2. If it's a one time gig, it can be entered as other income, and entered in TT, as I described above.
3. If he worked for an outside (not part of the college) company/employer training in his regular/anticipated line of work, it probably should be reported as self employment and self employment tax paid.
