It depends on how the robbery is charged. Robbery is charged as either a Class C Felony or a Class B Felony in Indiana. Class C Felonies have potential sentences of 2-8 years, while Class B Felonies have potential sentences of 6-20 years. Depending on the evidence, he may have defensible issues if he neither demanded nor received money, as you described the situation.
The fact pattern you described is more akin to an attempted robbery. Was your friend charged? What was he charged with? A robbery can be charged as either a Class C, B, or A felony. In the most basic terms the levels progress up depending on whether a weapon was used and whether or not injury or serious bodily injury/death was inflicted.
Even if it is charged as an attempt, an attempt robbery still carries the same levels as the principal offense. Your friend needs a lawyer.