Additional information is required in order to fully answer this question. There are different degrees of robbery that a person can be charged under. One is a felony in the second degree. A felony in the second degree can subject a person to a fine of up to $15,000 and a prison term of between 2 to 8 years. Robbery can also be charged as a felony in the third degree. In that case there can be a fine of up to $10,000 and a prison term of 1 to 5 years.
Again, depending on criminal history and the degree of robbery being charged the penalty can change. Either way, consultation with an attorney is probably the best option.
It depends in the level of felony. If you attempted to take a deadly weapon from a police officer, its a 1st degree felony which carries 3 to 10 years. If you it was an ordinary person and you had a deadly weapon or inflicted or attempted to inflict physical harm to the person, its a 2nd degree felony which carries 2 to 10. If you used or threaten to use physical force, its a 3rd degree felony which carries 1 to 5. The maximum fines range between 10k and 20k.
Disclaimer: I am not offering legal advice. I am just making suggestions for starting points for when you do speak with an attorney. Do NOT rely on anything I write and contact a lawyer.