Hi 

I am from India reached Germany on 17th January. My address is registered in Germany but I am yet to get an appointment for my blue card issuance application. My question is, in the meanwhile can I start processing family reunion visa with the 'Type D' visa stamped on my passport? Any help in this front is much appreciated.

No, you would have to wait for your B. card. I am not aware if rules have been changed recently....

You no need to wait for your blue card.

Your spouse can still apply for a family reunion based on your 'Type D' visa.

If the applicant holds a national visa and has prospects of receiving an EU
Blue Card in Germany, the subsequently immigrating spouse can also
receive a visa for the subsequent immigration of family members.

http://www.bamf.de/EN/Infothek/FragenAntworten/BlaueKarteEU/blaue-karte-eu-node.html