[Advaita-l] Rainbow Body

[KAMESWARARAO MULA]

Dear Sir's,                   When I was reading Tibetan Buddhist Monk's works I came across a word called 'Rainbow body'. Will it be same as Jivanmukta, i.e being liberated While living.
Did Adi shankaracharya talked about this or mentioned in any of his works? Why I was putting this question is that his nirvana from the physical world is by walking to kailasha.  Then how to reach state called breathlessness while living?
Sri Guru Padaravindarpana MastuKameswara