Were can i find the Timing marks on a megane 1.5 dci?

The top timing marks (Cam and injection pump) are easy to find. The cam has a hole for a timing pin to be inserted, and a mark on the pulley. Similar for the injection pump, there's a mark on the sprocket.

These marks align with factory white marks on the belt (I used a Gates Powergrip one)

The bottom pulley is a pig to align, as the serpentine drive belt pulley is not keyed to the crankshaft, so you need to get this off, set the timing at TDC, and MARK EVERYTHING CAREFULLY before removing the old timing belt.

Hope this helps,

Paul.