More weightage to a categorical feature for an Autoencoder model
Do you mean giving more weights to a selected part of the input? If so, then, I believe this is possible with neural networks. Each neuron is assigned a random weights at the beginning of training. You can just initialize the first layer of the neural network model with some values representing the desired weights and then freeze those neurons.

An automated way of doing this is by using attention mechanism which automatically provides more weights (attention) to a portion of the input data.