Relation between Faculty, Student and Course tables What should be the relation between following tables. Confuse whether i create an enroll table with student and course or courses_assigned table using faculty and course and then create an enroll table with a foreign key of courses_assigned table.  

This model is for an educational institute system, where users are students and faculty members. Courses are assigned to faculty members and students are enrolled in courses. 

System will show courses and their instructors(faculty members) to each student which he or she has to study and faculty members will see record of all students of a particular section which he or she has to teach.
One Course can have many Sections.  "One-to-many".  That is handled via a course_id column in the Sections table.

Many Students take many Courses.  "Many-to-many".  That is handled by a many:many table with two columns: course_id and section_id.  Note that you can find the course_id from the Sections table.

Facilty:Sections is also many:many.

I don't know where you are going with "OneToOneField".  Generally it is not good to have two tables in a one-to-one relationship.

Students and Facilty, though both humans (I guess), do not seem to be related at all.  Well, maybe you have "student teachers"?