Depends on so many things. Low tech, high tech, tank depth,fertilizer, co2. I use a 4 bulb t5HO over my 75g with dirt and co2 and it does more than enough.
I'm assuming you're new to this hobby. You should do some research about tank size, list of plants that you want to keep cause each plant has different needs of light or specific care, after you collected all the information then we would happy to help or make suggestions to your setup.
Also, keeping plant alive is far more difficult than keeping a fish alive and keeping plants far more expensive than a fish tank.