My child complained about being bullied at school. I feel like complaining to the school but I am good friends with those kid's mums and do not know how will they react or do I talk to them directly?

I would propose speaking to the teachers, get them to keep a look out for such instances and let them handle the bullying on the spot. This may avoid awkward tension between you and the other parents. Also, the teachers could intervene such that the children can learn that those are inappropriate behaviour. You can also try asking your child to report to the teacher when he/she is being bullied so that the issue could be addressed. It will be difficult for you to approach the parents without being present when the incident took place. Just some of my thoughts for your consideration. Regardless what you choose to do, remember to let your child know, so that he/she knows that you are attending to the matter.

who is more important here - the mums who are your friends or your child? i understand you don't want to suddenly take a step that could harm those kids in an academic area, but you have to do something about it. please speak to the school, and if required, withhold the names for now, or inform the staff about it but ask them to keep a watch without disclosing anything yet. that way, when the kids are caught bullying, the staff will have direct proof and will take the required action. also, i think if you are friends with the moms you should have a direct talk with them. they would understand if they really are friends.

bullying is a very serious issue that can have long lasting negative impacts on the child that you may not even be able to see initially. whether you are friends with the mom or not is irrelevant here, your child's safety and overall health is always more important. please make sure you bring this up with the school and give out a clear message that you will not tolerate any of this, and teach your child to speak up as well. take a look at this article, it may help https://www.theindusparent.com/yes-bullying-indian-schools-exist-heres-can

I would speak to the mums direct if you already know them. Just be aware that most mums do not like the word bully and may deny their kid bullying yours. What you want to do is call and say "hi this is .....I need your help with something..."

talk to the teacher and try to have a better understanding before deciding the next step