Voltage drop across any components in series is proportional to its resistance. 60W bulb has higher resistance than 100W bulb if both the bulbs were rated for same voltage. So higher voltage drop will be across a 60W bulb.
In parallel voltage drops will be same across both the bulbs but current through it will be inversely proportional to the resistance. So 100W bulb draws more current than 60W bulbs.
60W dissipates more energy than 100W bulbs when in series and 100W bulbs dissipates more energy when in parallel.