What is the exactly value & type of NvDCF maxTargetsPerStream Max value?

The type and value range can be found in Gst-nvtracker — DeepStream 6.3 Release documentation

Once the number of objects being tracked reaches the configured maximum value, any new objects will be discarded until resources for some existing tracked objects are released. Please check Gst-nvtracker — DeepStream 6.3 Release documentation