Hey kumudha,last year AIIMS did not upload the marks of students , no information about correct or incorrect answers as well. Only rank and percentile were given in the rank letter .So one can't truly comment on marks required based upon last year's results.However based on the previous results from Aiims 2015 and before , 145-155 seems to be a good score sufficient enough to land you in AIIMS Delhi.but do bear in mind that it also depends on the difficulty of the paper, the more difficult , required marks becomes less and more easier, it becomes more. i would sugest you to enrol in a very good test series and see for urself as to where you stand. if you are in top 10 or so, you have a real shot at AIMMS delhi, good luck buddy