Hi Nassha,
For low-cost spay/neutering, SPCA Selangor's Klinik Kembiri is a good option:
http://www.spca.org.my/what-we-do/sp...linik-kembiri/
If the cats are strays (not pets), you can ask MyAnimalCare for financial assistance to get them de-sexed:
https://myanimalcare.org/
TNRM (Trap Neuter Release Manage) is another organisation that helps with this:
https://www.facebook.com/Trap-Neuter...3709439694040/
Be strong! :-)