First of all, the safest way to start raising your Parisian Map levels is to click the green “Collect 5 Maps” button while in Paris which gives you 5 Parisian maps every 24 hours.
Then, you should start doing jobs, take part in fights and robbing and you’ll also be rewarded with Parisian Maps. Personally, I didn’t have too much success getting maps from the New York tier of missions but I’m still testing and will let you know as soon as I find out which tier is the most suitable for getting tons of Paris Maps in Mafia Wars.
However, if nothing seems to work, you can buy Parisian Maps from the marketplace, for a pretty high price of 14 maps per 10 Reward Points.
Do you have enough Parisian Maps?