# Example 1
ip_tensor_1=torch.tensor([[1,2,3],[4,5,6]])
ip_tensor_2=torch.tensor([[7,8,9],[10,11,12]])

torch.cat((ip_tensor_1,ip_tensor_2),dim=0)

# Output
tensor([[ 1,  2,  3],
        [ 4,  5,  6],
        [ 7,  8,  9],
        [10, 11, 12]])