I have broken like fifty (exaggeration) crimson alters in my world and I only keep getting the same three metals palladium, orichalcum, and titanium. I know there are other metals, but It just keeps blessing my world with the same three metals. I want the ores cobalt, mythril, adamantite, and chlorophyte. How can I get these different ores and why does my world keep giving me the same metals every time I break a crimson alter? Are some of these ores only on the mobile version or can I get them all on the pc version? I also have another question, how come every time I make a world I always get crimson why do I never get corruption?
The reason is:
When you create a new world, there is a chance that world will spawn a variant of an ore.
Variants don't do anything apart from look different.
Taking what I just said:
It's probabally that you're unlucky enough to have all the hardmode ores chosen to spawn their variants instead of the original ore.
Your only hope is to create a new world, activate Hardmode and hope that you get the main ores instead of their variant, as Altars never spawn in any other than the ones predefined to the world.
(So if you've got Cobalt, Mythril and Adamantite.. You're never going to see Palladium, Orichalcum or Titanium in that world. Same goes if you have Cobalt, Orichalcum and Titanium, you'll never see Palladium, Mythril and Adamatite.)
For reference: Taken from the Terraria Wiki
Copper may be replaced by Tin,
Iron may be replaced by Lead,
Silver may be replaced by Tungsten,
Gold may be replaced by Platnium,
the Corruption may be replaced by the Crimson,
Colbalt may be replaced by Palladium,
Mythril may be replaced by Orichalcum,
and Adamantite may be replaced by Titanium.
Meteorite, Obsidian, Hellstone and Chlorophyte remain the same in all worlds.
No matter how many Alters you break, the type of ore generated in your world will remain exactly the same. In other words, breaking more orbs will only cause more Hardmode ores of the ones that are already in your world to appear.
The type of ores present and the presence of either Crimson or Corruption in each world is picked randomly. If you have not been getting the type you want, it's merely because you're unlucky.
To obtain the other types of ore, you need to generate a new world and enter Hardmode in that world. Do note that the ores are, on the most part, equivalent, so there isn't much to be gained by getting the different ores. I believe (requires additional verification) that it is also possible to get bars/ores of Hardmode metals that are not present in your world by opening crates obtained from fishing.
You mentioned Chlorophyte. Those are generated once Hardmode starts, in the Underground Jungle biome. They will 'grow' by slowly converting mud blocks to more Chlorophyte ores, and do not require breaking any Alters (though mining them requires Hallowed or better equipment).
You seem to be very unlucky with those ores. All (or most) of the hardmode ores available in PC are available in mobile, but it appears that you seem to not be having the best of luck.
As for your other question, the Crimson/Corruption spawn rate is 50%. You may have a glitching version of Terraria, because they should have an equal chance of spawning.