"I like sitting on the balcony" would make more sense.
or "in the balcony" if it's at a concert.
'at' is incorrect
why sometimes is 'the' accepted without the use of 'ini' and sometimes is not ??
Ini means this . There is no "the" in Indonesian
You can use ini/ni and itu/tu to mean the, or para. But in general no there is no the in the language. Kinda cool tbh.
What about the -nya suffix? it is either "His/her/its" or "the" if his her or its is not mentioned in the sentence.