Social insurance as proof of employment

Hi guys,
I am planning to apply for ACS assessment but I have a problem related to the first date of registration at social insurance , it was after six months of employment start date. However, the date of employment on experience reference letter cover the whole period of employment, should I apply for ACS without this six months or apply with my reference letter and explain to the ACS about the issue, what do you think??

ACS will only need to see if you were paid to make to sure this was legitimate job.

Thanks Anil for your answer, I am afraid of getting negative assessment for the whole (10 years experience ) due to this unregistered six months of social insurance.