I am going to assume that your Normal time for D76 and Ilford Delta 100 rated 100 is that published by the Ultimate Dev Chart (whatever that is). Normal scenes will have about a 2 stop range, this is 3. You chose to expose more (5.6 as opposed to 11). This is a safer bet in my opinion - i.e get the shadows detailed and lets find a development time to control those highlights. So, this will be a N-1 scene or thereabouts. Take the D76 normal time you found in the published dev chart and reduce it by about 15% or 20% to start (I hope you have more than 1 neg of this scene, exposed similarly).

This is my simple recommendation. My REAL recommendation is to make some tests for your personal N and other times. If you do not have the means to do so perhaps someone can do this for you (e.g. the View Camera Store can send you a film test packet and all you have to do is develop the 5 or so sheets of Delta 100 at the times specified and then dry the film and send it back to them - they shall give you all the data you will need to enjoy your photography without worrying about what to do next).

Hope this helps, Francesco (www.cicoli.com)