If you can find the leak location, will be an Easy Fix !!
You will have to cut away all the silicone in the area and clean it away thoroughly. Wipe clean with alcohol and using aquarium sealant such as aqueon, apply a generous bead of sealant down the glass and spread evenly with fingertip or even a popsicle stick and allow to dry at least 24-36 hours. Leak test again and if done properly will not leak and you will have a permanent repair in which you can continue your set up of tank
THIS IS A LOT EASIER TO DO THAN IT SOUNDS