@akashdeepAEM
I believe you should use the latest version of cfm-graphql-index-def i.e. 1.0.5 irrespective of AEM 6.5.13 or 6.5.15, as far as it is AEM 6.5.xx
As you pointed out, the only difference is oak:index/graphqlConfig, which is not available in 1.0.5. As mentioned in AEM6.5.15 release notes, see the screen shot below, this Index was removed as it covers whole conf path as queryPath which is nothing specific to graphql or content fragments, hence it was removed to allow user add their own indexes based upon their query paths under conf.
![krati_garg_0-1670507196494.png krati_garg_0-1670507196494.png](https://experienceleaguecommunities.adobe.com/t5/image/serverpage/image-id/51259i896D046F9472BC19/image-size/medium/is-moderation-mode/true?v=v2&px=400)
![krati_garg_1-1670507420639.png krati_garg_1-1670507420639.png](https://experienceleaguecommunities.adobe.com/t5/image/serverpage/image-id/51260iBC9C2CEAF4CFBB03/image-size/medium/is-moderation-mode/true?v=v2&px=400)
Hope this helps