Assuming your view code is:
t=[]
t.extend([('a',1),('b',2),('c',3)])
(and not as stated in the OP)
{{ t.0.0 }} is like t[0][0] in Python code. This should give you “a”, because t.0 is the first element of the list t, which itself is a tuple, and then another .0 is the tuple’s first element.
{{ t.0.1 }} will be 1, and so on.
But in your question you are creating a tuple and trying to access it as if it is a dict.
That’s the problem.