Hi

That will not make any substantial difference as the educational eligibility criteria for a standard 3 year LLB program is graduation. The admission to this course is based on either entrance exams or marks of your qualifying exam. What marks you will enter will depend on what is asked in the form but since the criteria is graduation only that matters irrespective of your postgraduation score. No benefits will be given if you are overqualified but it will help you to smoothly move in your academics as you are already a PG provided it has some relation to the course you are pursuing.

Hope this helped!