@Raj2310 ,
(a) Can you continue to hold the vested RSUs even when you have abandoned your GreenCard and live abroad ---- YES
(b) Is there any tax advantage in selling these here in the US as opposed to sell these later in India ----- Depends on the then exchange rate and if these stocks are listed in India. If these stocks are tradeable ONLY in US ( like OTC stocks ), then you have to sell these through your broker in the USA, considered as US sourced income and be taxed both in India and US. Note that as NRA ( Non-Resident Alien ) the tax rate may be the flat 30%. -- depends on the tax treaty.
(c) Note that being a Long-Term Resident, when you file for abandoning your residency ( I-407 , I think ) you also have to file a form 8854 to cancel your Tax Residency. IRS may want you to pay tax on the gain of these RSUs till date ( thus increasing your basis ).
Please this from the IRS ---> Expatriation tax | Internal Revenue Service (irs.gov).
Is there more I can do for you ?
Namaste ji
pk
