By six months of age head control must be complete. It is necessary for the acquisition other milestones. if your son has still not attained head control, he will require a complete neurological examination . please take him to Pediatric consult in person.

Is there any perinatal event like delayed cry or premature or difficult labour ??? Child will get the complete head holding between 5 to 6 months of age. If he sits with support and roll over by herself there should be no developmental delay, u can for wait for 1 month.

You must come and consult

Mild head lag / wobbling may be present at 6 months age. You mentioned that child can sit with support & can keep head high which are good signs.

If he cam sit with support and actually do all the other things you say , then motor milestones are normal . Head may still wobble a bit during sudden movements . That is normal . So keep a watch and consult your pediatrician for complete developmental assessment . Watch for other milestones like smiling , vocalisation , cooing , his hand movements etc .

If your baby had an uneventful birth and is sitting with support by now,it is unlikely that he has a head lag.Get a checkup done by your Peadiatrician once the COVID crisis is over for a developmental assessment.