It can be challenging to find an organization to support. Most welfare and regulation organizations use the term animal rights when that is not actually what they support. Or, they claim to support animal rights but all they do is support campaigns to regulate animal use instead of taking a stand against animal use to begin with; their activity makes animal use more efficient and profitable and makes the public think they are achieving moral victories and that we are meeting our moral obligations. They make people feel good about using animals and thereby prevent realizations that we ought not be using them at all. In other words, they tend to support animal use rather than oppose it.
Furthermore, many of these organizations use immoral or contradictory arguments against animal use; they commit to a sexist approach on the one hand and argue on the other that just as sexism is wrong, so too is speciesism.
Furthermore, they engage in various gimmicks and theatrics that just reinforce the stereotype of animal rights and veganism as strange and crazy or naive. Most of their activities are not geared to promoting veganism and basic rights for sentient beings but rather to fund raising for their own activities. Some of them make a fortune this way and they use the money for these misguided tactics that merely contribute to the problem rather than actually impose it.
Most people don't even know there is a serious movement with reasonable and intelligent argumentation; they think it is just people screaming slogans at the door steps of biomedical institutions or throwing red paint on people or wearing big bunny costumes or going naked rathe than wear fur etc.
These organizations often defend their tactics by claiming that without getting public attention, the public will not be aware of the problem and that they can promote welfare and regulation toward a rights end. The problem is that the tactics alienate people or promote a flaky commitment at best and the welfare and regulation endeavors are just making matters worse. In other words, their tactics are counterproductive and misguided.
But, again, if you are looking for an organization to support financially or otherwise, look for this. Look past their primary claim to advocate for animal rights. Look to what they actually do. One way to tell what they really stand for is to look at their actions. Are they supporting or praising in any way animal users? Do they praise McDonalds or KFC for using more comfortable chicken cages? Are they out fighting for laws that make animal use more humane? Remember, certainly less torture and suffering is better than more. But, nothing will change for the better unless we advocate against animal use rather than merely regulating it. The problem is that we use animals at all, not how we use them. Just as their is no such thing as humane rape or humane murder or humane torture, there is no humane nonhuman animal use.
Just look behind the "animal rights" term when choosing an organization to support.