Question

which one is correct? .. a) Truely b)Truly

Answer 1

Truly  is the only acceptable way to spell the adverbial form of the adjective true .
so, truly is correct

Answer 2

 Truly is an adverb that means being done in an honest manner.Truly also used as a closing in many formal letters.
        example: Abhilash signed the letter,"yours truly, Abhilash" 
But Truely is a misspelling of truly.It probably stems from the fact that the root word, true, is spelled with an E as well.Nonetheless, truly is not an accepted spelling of this word