As Herman says, there will be an expectation that you would have raised any concerns at the time, not least because it can be more difficult to investigate what happened months after the event.
However, you need to focus on other matters. Your appeal is most likely to be decided on the basis of alternative academic evidence and reasons for wanting a place.
What is the procedure for placing an appeal, http://www.elevenplusexams.co.uk/appeal ... cation#b51
Is it done in the current school, or by the council,
Should we do the appeal ourselves, or is it has to be done through the school.
You appeal to the relevant admission authority. (If the school is responsible for its own admissions, you appeal to the school.)
What is the deadline for the appeal, http://www.elevenplusexams.co.uk/appeals/general#a2
On the CAF, shall I place Langley Grammar as the first choice or it does not matter if it is the second.
Put the schools in your true order of preference.
Should I do and see the head teacher at Iqra or this is not related.
I think you should see the head because you will need as much academic evidence as possible to support your appeal.