You mentioned that your tlt-infer result with resnet10 and resnet18 is not good, what is the training accuracy result during the log? If not meet your requirement, you need to trigger more experiments to get a higher training result. Try to finetune hyper-parameters, add dataset, etc. It is a topic of training.
You also mention that your resnet50 tlt-infer result is good. What is its training accuracy result during the log? Can deepstream run well with this resnet50 model? If there is a gap between deepstream and tlt-infer, you need to check deepstream config firstly.