My father works in a haram bussinness, his bussinnes has been doing bad for the last two years and he barely provides for the family. Our other source of income is my sister. I am a high school graduate and I want to study medicine. In order to get into med school, I have to do a two-year pre-med course. My question is, since my sister is the one who will pay for my fees and since she cannot provide for the family and me at the same time, can I present a fake certificate that can get me into med school directly so that I can finish early and help my sister in providing for the family through halal means?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger. 

It is impermissible for you to do such a thing given the prohibited cheating and deception involved. You should either seek a lawful means to earn the needed money to study medicine or choose a different field of study that you can afford. It is impermissible for you to submit a fake certificate to skip the two-year pre-med course.

You should bear in mind that whoever leaves something for the sake of Allah, Allah will substitute him with something better, and whoever relies on Allah as due, He will relieve his distress and hardship. Allah, The Exalted, says (what means): {…And whoever fears Allah - He will make for him a way out and will provide for him from where he does not expect. And whoever relies upon Allah - then He is sufficient for him...}[Quran 65:2-3]

Allah knows best.