If USCIS receives the document - it means that i have come under the quota

My application was send to USCIS on 6th june - So will they only accept my application if they have still quota left on 6th June - or they will accept it withour checking anyuthing - and later they can send denial saying the quota is over - is this possible ?

If your petition reached USCIS on 6th June and the quota was open on that date, they will accept it - provided the petition is filed properly (with all fees and other required documents).

Hope that helps.