Could you tell me what homeopathic remedies to do you recommend to treat autism?

None proven effectiv. There are no homeopathic substances that have been proven beneficial in cases of autism by double blind controlled studies.
None. There is no evidence based research supported homeopathic treatments for autism.Too many people fall prey to false claims of effectiveness from unproven remedies. See http://mentalhealth.Gov/health/publications/autism/complete-index.Shtml.
None. We have witnessed megavitamin therapy, secretin, and enzyme therapy pass thru our lives with zero success.Let us see legitimate, clinically proven results before we endanger the children with potentially dangerous regimes.
None. Autism responds to behavioral therapy like applied behavioral analysis (aba), there are no magic medicines (traditional or homeopathic).
Safe. Many people subjectively feel that homeopathic remedies have helped them. While some alternative therapies might be potentially harmful, homeopathy is very safe.
There are no. Medications that are proven to be effective in treating the core symptoms of autism, be they homeopathic or traditional prescriptions. Arbaclofen, not yet marketed, has been proven effective for social withdrawal in kids with fragile x & is being studied in autism.See www. Quackwatch.Com for specifics. The early denver treatment model & applied behavioral analysis are evidence-based therapies.
Big topic. Autism is a very complex topic, involving many types of physicians and other health practitioners. All have opinions. Homeopathy treats the individual, not the disease -- so helpful remedies depend on thorough case-taking by an experienced homeopath. I suggest you read "the impossible cure" by amy lansky phd. In it she shares the story of her son's autism, and his cure through homeopathy.