Shanto_Islam:

tensor([5, 2], [6, 3], [7, 9], [[4, 5], [1, 4], [3, 8])


I am guessing this should be
tensor([[5, 2], [6, 3], [7, 9], [4, 5], [1, 4], [3, 8]])
In that case, you can use:
tx=torch.cat([t1,t2],dim=0)