Sergio Ramos is one of the best defender in the world. He is about 35 years old. But he is still a world-class defender. Many teams would be interested in taking him if Real Madrid releases him. A defender like him multiplies the strength of the team. Real Madrid now has no skilled striker except Benzema. Now if they release Ramos then their defense will be weakened.
Let's not get ahead of ourselves, sure Ramos is a great player but we are talking about over a decade of being hated by people as well, not that he is not a good defender but he is too "aggressive" and that is why he gets carded all the time as well, and if you look at how many players he injured as well you will see the reason why he is hated as well.
None of this means he is a bad player, but when you are a player who doesn't care what you hit, ball or player, you do end up with a bit of an advantage over other defenders who are more careful. So he may not find any decent offers, I am not saying zero offers but he will probably never play on a team at Real Madrid level, he could find some Sevilla level if he wants to, not just in La Liga but just Sevilla level all around the world, that is all he can get. Best option probably would be Leipzig which is a great team if you ask me because they are selling their best defenders to Bayern this year.