How big? How strong? How much corrosion resistance?
4410 (with higher C) would be the strongest, but it would require a post cast quench and temper heat treatment and it would have the lowest corrosion resistance. It will also have low ductility and be magnetic, though is would cost the least.
201 (especially with added nitrogen) will be reasonably strong, not too costly, and have decent corrosion resistance.
There are specific cast grades for these alloys, with special chemistry restrictions. You need to look at casting specifications.
304 = ASTM A351 CF8
316 = ASTM A351 CF8M
410 = ASTM A217 CA15, I have also seen C12 as a 410 equivalent but the chemistry does not match as well.
I am not sure the equivalent of 202. I have never cast anything with that much Mn in it. CF10SMNN is kind of close. CG6MMN is as well but with more Cb and V.
CF8 and CF8M both have a specified 70ksi tensile, 30ksi yield.
CA15 will have a specified 90ksi tensile and 60ksi yield.
CA15 will be cheaper from a material perspective. It does not have much alloying beyond the Cr.
None of the three are terribly difficult to cast. CF8 and CF8M would be the easiest from my perspective.
Now, I just make the stuff, I don't get into material selection. These have different uses and just because a material is called stainless that does not make it equivalently corosion resistant in all conditions. Proper material selection is more than just picking a stainless steel with the correct strength and cost.
There is a lot of cast 201-202-204 stainless out there, most with lots of N in them. When Ni prices went through the roof last time the usage of 2xx grades also exploded. Current data shows that globally there are roughly equal amounts of 2XX, 3XX, and 4XX being used.
I cast a lot of 204, but that was 30 years ago.....
The question is vague and does not merit a response, unless specific information is provided.
I have produced parts as CA15 alloy, 200 series etc. All the alloys mentioned can be cast, but with a caveat, the mechanical properties cannot be compared with a wrought alloy.
"Even,if you are a minority of one, truth is the truth."
410 have the most strength in other varieties. As it approximately contains between 0,1-1% C, it even can be toughened at slow cooling rates. However, others contain less than 0,1% carbon. I think you should not expect more strength.
Caveat to the 410/CA-15 recommendation: weldability, at least with matching filler metal, is poor, for same reason that castability is not great - 410 has a very wide freezing range.
If you can live with little corrosion resistance sure use 410, but remember that you will have to quench and temper, and end up with very low ductility. The C has to be very carefully controlled to end up with the correct microstructure.
For reasonable cost, corrosion resistance and strength (if you want a balance) would be the 202/201,
OR maybe a lean duplex grade, one of the 20-21 Cr, Mn + low Ni might be a good option
