Rewards are based on intention. If someone establishes a college and he intends that those who shall get education will serve the nation in future, then definitely it shall fetch rewards. Donations may also be collected from Muslims for it, but it shall not be lawful to collect zakah as it is necessary to make the poor and needy ones the owner of zakah amount. If after becoming a doctor or engineer or advocate one serves the nation with honesty then it is a source of virtues. But whatsoever situation comes in our observation is also obvious that after acquiring these sciences most of the people have made these sciences only the source of income. However, if your intention is good then you shall get its reward; specially if these colleges provided solid religious education then it shall be more useful and shall carry rewards.
Allah knows Best!
Darul Uloom Deoband