Did Sakyamuni Buddha ever mentioned in his 49 years of teaching a bodhisattva or a future bodhisattva name Guru Rinpoche ??
Tibetans claim so.
Both of them attained enlightenmemt differently , one of them through consort practice .
Tibetan Buddhists claim that Shakyamuni Buddha attained enlightenment also through consort practice in a previous life, took birth in Tushita, waited for the right time and manifested a sutric nirmanakaya birth. Shakyamuni did not *primarily* teach tantra and left that mostly to GR (who is said to also be an emanation of Shakyamuni).
Consort practice is a distraction for us. The main thing is just like in Theravada: practice virtue, abandon non-virtue, purify the mind. It's just that the methods (the details) are different. Consort practice is for very high bodhisattvas.
Followers of Guru Rinpoche and followers of Buddha do different practices.
No, GR taught Buddhism and followers of the Tibetan Vajrayana (followers of GR) do the same practices as the "followers of Buddha" (presumably this means sutric practicioners sine you have proposed this dichotomy). However the sutric practitioners do not practice tantra and certainly not inner tantra.
Do they contradict each other ?
No. But Shakyamuni Buddha primarily taught non-tantric methods. GR primarily taught tantric methods.
_________________Kirt's Tibetan Translation Notes
"Only you can make your mind beautiful."
HH Chetsang Rinpoche