On the basis of circular as provided at
/blog/post/280521/105it can thus be concluded that ration card/s can be produced as relevant identity proof while booking Tatkal Tickets. However, it should be mandatory for the Ration Card to contain the photographs for the person who are willing to undertake the journey and are keen to produce Ration Card while booking and while cross-checking in the train!!
Also, it should be noted that only those identity cards issued by State/Central Government should be accepted which are having serial number/s.