Connecticut General Statute section 14-12(a) states that no motor vehicle shall be operated or towed on any highway, except as otherwise expressly provided, unless it is registered with the commissioner....(2) a resident of this state who operates a motor vehicle he owns with marker plates issued by another state shall be fined not less than one hundred fifty dollars nor more than three hundred dollars. If the owner of a motor vehicle previously registered on an annual or biennial basis, the registration of which expired not more than thirty days previously, operates or allows the operation of such a motor vehicle, he shall be fined the amount designated for the infraction of failure to renew a registration, but his right to retain his operator's license shall not be affected. No operator other than the owner shall be subject to penalty for the operation of such a previously registered motor vehicle.
So the typical fine for driving without registration appears to be between $150 and $300 however if you just have not renewed your registration within 30 days of it expiring than it is an infraction that comes with a lesser fine. From the last infraction fine schedule we saw for CT it listed this offense as being $93.
If you were cited for driving in Connecticut with expired registration you should contact the court listed on your ticket to find out what exactly your penalties will be. The $93 might be the fine amount you'll pay or it could be a base fine which court costs, etc are added to. Also if your registration was expired for over 30 days this may come with a heftier fine amount.
For inexpensive car insurance for CT, follow this link.