Question
I believe this might be due to C6 misalignment. Would massage therapy a contraindication for this issue?

Answer
Cinda,

Tingling in thumb/index finger is about a C6 "NERVE" issue, not a misaligment issue.   It can also come from nerve entrapment in the area called the thoracic outlet (the zone above your collar bone and along side your neck.   It can also be from a problem in your arm.     Massage is safe, but if the numbness is not resolved, then you must get it checked out by a chiropractor or medical physician with good examination skills.   Avoid x-rays...    Physical examination, if done well, will determine what the problem is and will better determine what the best course of action should be, e.g. manual treatment or further imaging diagnostics.    

'Hope this was helpful.  

Dr. G'