Would it possible to stream from CCTV to KVS to IVS?

Kinesis Video Streams (KVS) supports two types of video streams - the original version using its own API for ingest and delivery (not a standard protocol such as RTP, RTSP, RTMP, etc) or WebRTC. You can't mix these protocols (e.g. KVS API in, WebRTC out). A quick look at the camera specification doesn't list KVS or WebRTC as a supported protocol, so you would need something to convert the video, either using the KVS Producer SDK (for the KVS API) or WebRTC.

KVS does not currently support RTMPS output which is the only ingest protocol currently supported by IVS. Therefore, you would need an intermediate 'transmuxer' to convert the output of KVS to RTMPS. You could use MediaLive (it supports HLS input which can be provided by KVS) and RTMPS output.