ANSWER:

You can combine the intention of fasting the missed days with Mondays, Thursdays and the white days (13, 14 and 15th of the lunar month providing that you intend at night that tomorrow is making up a day of missed Ramadan.

If i fast in every Monday and Thurs. And also in 13,14 and 16. Will it be consider as recovering my missed fasts in ramadan, and 6 days Fast in shawal also common benefit of fasting in these days. If not than do i need to recover all my 6 missed fasts in a row first. and then start the 6 days ? Or i can also cover my missed fard salah after sawal.