When revolution comes the powers that be will have to decide how to respond, and their response can reveal much about the reasons the revolutionaries have taken up arms in the first place. Supporters of the regime are as important to the course of the revolution as the revolutionaries are. An officer who feels they need to make an example can easily make martyrs out of protesters. On the other hand, it’s easy to storm the palace when conscripted soldiers realize that they would rather not shoot at their friends and family.
First, why do they care? There doesn’t have to be just one reason, since they may be just as divided in their aims as the rebels. But generally the people propping up the government should have some reason for doing so. Are they part of the ruling elite? Do their businesses benefit from tax incentives or kick backs? Is there salary paid by the regime? Are they common people who just want to continue on with their lives and don’t like the disruption the hooligan rebels have caused?
Supporters may not even be from the same country in which the revolution is taking place. A neighboring autocratic regime may fear that a revolution in their region will encourage revolutionaries at home and step in to ensure that the rebels fail. Foreign commercial interests may also see the rebels as intolerable disruptions to their operations. Even opponents of the regime’s actions might be against the revolution if they see the regime as a necessary evil, or a bulwark against something worse. This ends justifying means attitude might be found in settings like Warhammer 40k. The Imperium’s treatment of its subjects is detestable but also far better than what life would be like under the xenos threats that constantly test its strength. Assuming the xenos would allow human life to exist at all.
Responses to rebellion might be inconsistent and lack the force of conviction even in autocratic regimes. Rulers can find themselves torn between advisers and political interests who each have their own pet method for rule. They might offer concessions one day and dismiss parliament the next. But this seesaw behavior will only erode trust in the government and make the regime’s instability even more obvious.
A forward thinking ruler will likely offer concessions. Better to keep some power and grant the people more rights than find your head on a chopping block later on. That said, plenty of autocrats will stubbornly hold on to power out of a sense of arrogance or may be convinced that foreign support is coming. Some may not realize how widely disliked they are or believe that ruling is a job that they were appointed to by God and thus must uphold it. In some cases an autocrat who sincerely believes this might actually be less willing to use force, and have to be convinced by advisers that it is time to finally call in the army.
Adding to this is how many of the autocrat’s subjects also believe in this divine purpose. Rebels with backing and strong leadership can attract support through the promise of future legal and financial incentives. But religious incentives are harder to overcome. Someone who believes God is on the side of the autocrat and against the rebels is going to be harder to convince than someone who has picked a side simply for personal gain.
The darker motives of the rebels should also be considered. Few things make loyalists out of people than a belief that they will face retaliation following a revolution. An local group rebelling against a distant empire is all well and good, but how will they treat other native groups that are not them? Do the rebels fight for rights for everyone or only for people like them? One group wanting representation for themselves does not always mean that they want representation for others.
Above all, the most important part to coming up with regime supporters is deciding on their motivations. Few people are actually truly evil, they just want to survive, do good by their families, and may have different ideas of what government should look like. You can make a character sympathetic but still do bad things. You can also make them not entirely wrong. Make your reader grapple with these concepts, and make your revolutionaries prove to the audience that they are in the right.