While most colleges will want to see a well-rounded high school curriculum, the specific number and type of electives are not standardized. Some colleges emphasize a certain number of credits or courses in specific areas (like science or math), but this is not a fixed number across all colleges. Others place more weight on GPA, standardized test scores, extracurricular activities, and essays.
A high school counselor is the best resource to understand the specific college application requirements and to help a student create a suitable high school program to prepare for college applications.