1. to try or plan to achieve something
aim for something: We should aim for a bigger share of the market
aim at something: The government is aiming at a 50% reduction in unemployment
aim to do something: They are aiming to reduce employment by 50%. We aim to be there around six.
aim at doing something: They're aiming at training everybody by the end of the year
Ref: gmat-grammar.blogspot.com/2007/04/aim-to-vs-aim-at.html