Can I take the Texas pre-license course with more than one school?

Yes, you do not have to complete all 6, 30-hour courses with one school.
Once you complete any of the 30-hour pre-license courses, you will receive a Certificate of Completion for that course.
When it comes time to submit your license application, you must include copies of all 6 Certificates. The Certificates may be from more than one school. TREC only requires that they receive one Certificate from each of the 6, 30-hour courses.