My cats have been fighting alot, there are many cats in my locality that newly came in so I think it's because of that. How can I make them friends again?
Initially the new pet should be kept in a separate room for a few weeks. As the cats produce their own scent which they use for territory marking along with urination, it's hard for old cats to accept the new ones. During this separation period, you can switch the cat's bedding on alternate days so that they get used to each other’s scent. Get them toys separately and swap between them. Give them playtime for one hour together under your supervision. Give them feeding and water bowls separately.
During the playtime use treat to praise them and introduce them. Use the words Good , Bad, yes or no, happy and sad and lastly get them neutered to suppress male dominance/aggressiveness.