This comment could be cleaned up a bit.  It's also a little confusing as currently worded.  After reviewing the code, I'd suggest:

/*
* mode: MTK_CALL_INDIC_MODE_AVAIL: indicates that the specified call can be answered.
*            MTK_CALL_INDIC_MODE_NOT_AVAIL: indicates we are busy, and that call specified 
*            call cannot be handled.   call_id and seq_number are used to identify a specific call and
*            usually are taken from an incoming RIL_UNSOL_INCOMING_CALL_INDICATION.
*/