See for aiims, they don't publish marks. They publish percentile.  50 percentile for general category is the eligibility but for a good rank you need good score. A 60 percent score that is 120+ is safe. Last Aiims that is filled up is usually Aiims Patna. However a score of 120 confirms your seat. 

Dear Anijima,

The cut off depends on the difficulty of the paper which varies each year, so, it would be meaningless to state the cutoff marks. What matters is the rank.

As per the AIIMS MBBS cutoff 2018, candidates belonging to General Category requires to score at least 50% marks in the Entrance Exam. While those belonging to OBC requires to score at least 45% and the SC/ST candidates need to score a minimum of 40% in order to qualify the exam.

Try to score 125+.

May your wishes come true. All the best !