RSA code giving result after more than 10 minutes
What we've got here is a so-called naive implementation, which doesn't consider time complexity of power-then-modulo operations involving large integers. I'd recommend you to read up on square and multiply, exponentiation by squaring, binary exponentiation, for a bit of context. Typical naive implementations have O(2m) complexity, while optimised versions could achieve only O(m).
If you replace the commented-out code with the uncommented, you'll get significant execution speed improvements:
# ctt = pow(no, e)
# ct = ctt % n
ct = pow(no, e, n)
...
# dtt = pow(ct, d)
# dt = dtt % n
dt = pow(ct, d, n)

See Python built-in function docs for more details of what I've done.
Please note I did not verify reminder of your algorithm.