default or selected kernelversion does not have config value CONFIG_NET_CLS_TCINDEX.
Result is shown for kernelversion 6.5.1

Traffic-Control Index (TCINDEX)

modulename: cls_tcindex.ko


Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>QoS and/or fair queueing
└─>Traffic-Control Index (TCINDEX)
In linux kernel since version 2.6.12  
Say Y here if you want to be able to classify packets based on
traffic control indices. You will want this feature if you want
to implement Differentiated Services together with DSMARK.

To compile this code as a module, choose M here: the
module will be called cls_tcindex.

source code: