If it is blocked as in the door is not available, then you may want to try to find a panel to hack to open it. If the door itself is blocked, then augmentations really come into play. For example, you may need to punch through a wall (an arm-augmentation) or lift whatever is blocking it (may require an arm-augmentation if it is a heavy object). It may just be necessary for you to find a vent or small hole to crouch through, however. No room will ever be completely inaccessible if you can see inside it.