5 months old baby is showing symptoms of infant spasms is there any pediatrician/neurologist who can help around Johannesburg?

Wouldn't know. You have posted on the HT public information site based in California. We have volunteer physicians based primarily in the USA who answer medical questions when you describe a problem. We have no access to information about local healthcare systems or providers around the world where the site is viewed. You need to contact your healthcare network or providers for such questions.
Need Pediatrician. Start with your general pediatrician! What does she say about the baby’s development? Babies can twitch a little upon falling asleep, but twitching upon wakening is worrisome. Get help right away and good luck! Try “ pediatric neurologist johannesburg“ into google .
Referral. I would advise having an appointment with Pediatric Neurology. Your PCP can provide a referral.