If one intends to ordain, say in Thailand, and one lives in India - would it be right/moral to ask support from one's parents (since one is not yet ready/able to support oneself)?
If they support you then it is OK. You should ask for support according to their faith and ability. Normally supporters and family are the same words in pali. It is listed in the Metta sutta as family "kulesu", often translated as donors.
However, one should live a modest life and ask for only what one needs. Asking for sangha needs is much better. It depends on your family's desire. There could be a problem with receiving donations from your parents if you gave them money beforehand. I am not sure of the exact details.
While I do not know the exact rule for this, I do remember asking about this with a monk who gave his parents money and then asked for a computer specifically saying, "Use the money I gave you.". The teacher (Sayadaw U Kovida, paauk) said this would be unallowable. (This transaction never went through, by the way)
To avoid a situation like this, if you do give your parents your money, you should say, "This is yours, use as you wish." Or "Do not use this for me or to monks." Then when you ask them for things, whatever they do, it is their money and donations are from their own doings.
It is actually legal for them or even a bank to have money for you as long as you do not use it. This is how one ordains temporary in a vinaya tradition. If you decide to stay full time, things can get complicated with bank accounts (if you are one who cares about vinaya). Some need to temporarily disrobe to handle their affairs. According to ratapala sutta, he told his parents to throw the money in the river.
Yeah, It's not an immoral act to ask for help, especially your parents. You shouldn't become dependent though, but as long as you really need it, there shouldn't be any problem.
Aside of being not allowed to ask lay people for nearly all of the requisites, a monk (Bhikkhu) would be allowed to ask his "near" family (blood relatives) members without violating the rules. Some Sanghas and sects expand near family to the seven generations, which in Asia then mostly includes the whole paticular village one lives.
If one actually does (ask) or not, is another matter, since from a kammic view (e.g. accumulating certain debts) it has it's impact as well. Especially if not really familar with Dhamma it can cause lot of troubles.
It's maybe worthy to note that monks for the most, especially from a modern or western backround, asked or not usually can not aspect much support or help from family. One leaving home therfore should be clear that he will be most dependent on the "new" family, the ideal Sangha and those following them (sometimes "only" cultural).
Generally one is good advices not to hope or count on support one was used to gain once having left home.
The other extreme is merely reality in SEAsia, where sure 80% and more monks maintain their lifes mainly on the family. A normal situation that as side effect let people mostly think "if he needs really something, he will ask his family", especial "problematic" in regard of medicine, if being someone have left home actually.
There is also a kind of new wave (certain western monks are included): children of rich people, with full support and living like such... they are really annoying when going begging if like or call mommy.
So all in all, a matter one should think very carefully about.
would it be right/moral to ask support from one's parents
In short: "Right is given to do so, yes. From a moral point of view: really if even better do only in cases of real emergency."
(Neither is it good for once conscious nor does it shine bright in regard of the Sanghas-members. And althought generally allowed one is actually easy and fast in transgressing a heavy falt: corruption of families, Sanghadisesa 13. Something actually very common sadly.)
Nevertheless, one support one would need from ones parents anyhow: the acceptance that one may leave home.
[Note: This is a gift of Dhamma, not meant for commercial purpose or other low wordily gain by means of trade and exchange]