Shri wrongan,
It is Bheema Saanti (to be conducted at the beginning of the 54th. year of life : bhee-ma means 54 according to kaTapayaadi system) and Ratha Saanti (72nd. year beginning, i.e., on completion of 71 years of life). But there was a modern concept of celebrating the 70th. birthday as "Saptati" among some people. So, it is possible that people made one package of Bheema, Ratha and Saptati and are celebrating it on their 70th. birthday (completion of 70 years of life).
For an orthodox braahmana all three (none of the above) are not suggested by the Dharmasaastram; these are done (esp. bheema Saanti and Ratha Saanti) only when the horoscope shows a definite "gaNDam" at any of these ages. According to astrology, certain dasa configurations give rise to such "gaNDam" which means great chance of death.