Two classes: University and Student

gistfile1.txt

public class Student extends RealmObject {
    @PrimaryKey  
    private String id;
    @Required    
    private String name;
    @Required    
    private Date birthday;
    @Required  
    private String email;
	    // getters and setters
}
public class University extends RealmObject {
    @PrimaryKey
    private String id;
    @Required
    private String name;
    private RealmList students;
	   // getters and setters
}