On their website, it says class of 2024 SAT 25th percentile is a 1500. Is this true? It seems extremely high for any school. Could it be because Columbia school of engineering is boosting it since it’s combined?
Thanks
While it’s high, that’s not unusual for most private T20s, given their small class sizes (compared to public universities) and high competition. Most colleges report SAT/ACT percentile ranges on their CLASS PROFILE based on the entire class, not subdivided by school (though some colleges may include this information, or acceptance rates by school.)
Keep in mind that there are still 25% of students at Columbia who are admitted with a score at or below a 1500 or 34, though some of these may be those with hooks. Engineers, at most schools (T20 or otherwise) tend to have higher stats than other majors (above 50th percentile is best, though there are exceptions.) For extremely selective schools like the Ivies, apply widely (safeties, matches, and reaches) and hope for the best! 
Hope that helps!
The middle 50 percentiles for admitted students is 1500-1560. The middle 50 percentiles for enrolled students would be lower.
Columbia does not post its Common Data Set, but we can see section score ranges for enrolled students for class of 2023, EBRW 700-770 and math 740-800. https://nces.ed.gov/collegenavigator/?q=columbia&s=all&pg=4&id=190150