Hi @mukesh.
Sorry for the confusion I will make the docstring more clear.
TMCMC and CATMIP are both slightly different versions of the family of Sequential Monte Carlo (SMC) algorithms. There is only one SMC method implemented in PyMC3 and is based on those two algorithms, with a few additions (that is should check if they are properly cited).
To used SMC in PyMC3 you write something like pm.sample(step=pm.SMC()) as explained in the notebook you mentioned. The function sample_smc is used internally by PyMC3.
I hope this helps.