h4 to h1 conversion question

[telugu3701]

i am planning to do conversion from h4 to h1b ..i have around 6 months of left for my 6 years of h1b max out and recently my i-140 approved.

my attorney is saying we cannot get total 3 years of h1b tranfer validity as ac 21 wont work since 6 years is not completed.is that true?

my last h1b status was in nov 2018 after that i moved to h4 ead .

the current employer which i am working on h4 ead he dont hold my previous h1b (2018) so they need to do a h1b transfer.

Is that true we cannot get 3 years of extension when 6 months of left in h1b max out even my i-140 is approved.

Please give your inputs on this Thanks in advance