acdindian wrote:given that you can only have a 6 month visitor visa in a span of 1 year)
There is no 6 month in a year rule.
What is not allowed is residing in the UK in the guise of a visit visa, through frequent or successive visits. This
earlier post for another user summarises the situation. Also see the recently updated
visit visa guidance.
Be aware that recent cases posted on these forums seem to suggest that having repeated visits to family in the UK is leading to rejection of future visit visas. Visit visas are not a means of bringing elderly parents to reside in the UK.
As
Wanderer has mentioned above, why would your parents need to visit the UK again so soon after having spent five months here? If it is so that they can stay with family, that is residing and not visiting.
Also see this
recent case of the visit visa application for the mother-in-law of a moderator on these forums getting rejected.
I am not a lawyer or immigration advisor. My statements/comments do not constitute legal advice. E&OE. Please do not PM me for advice.