They are all different.
"consensus" means a general agreement. So "social consensus" means that most members of society agree about something. "There is a social consensus that there should be a minimum wage."
"compromise" means an agreement in which each party to the agreement gives up something that he wanted. So "social compromise" refers to an agreement between members of society, in which each side makes concessions (doesn't get everything it wanted). "Some people advocated for the continued illegality of marijuana. Others wanted its complete legalization. Eventually a social compromise was reached which permitted the sale of marijuana, but only for medicinal purposes."
"reconciliation" means to restore good relations after a dispute. So "social reconciliation" refers to restoring good relations between different members of society. "Certain ethnic groups have been opposed to each other for decades. Let's hope there can be a social reconciliation someday."