Both 一些 “a few, some” and 有的 “some” modify a noun or a noun phrase. The difference between the two is that the noun or the noun phrase preceded by the former is usually the object of the verb, whereas the noun or the noun phrase preceded by the latter must be the subject.
The word 一些 indicates a small but indefinite quantity, e.g. 一些老師 (a few teachers) and 一些水果 (some fruit). Since the noun phrase with 一些 has an indefinite reference, it is normally the object of the verb:
我們去機場接了一些新生
We went to the airport to pick up some new students.
The meaning of the word 有的 is “some but not all.” It usually indicates a portion of a larger entity:
這些樹，有的(樹)高，有的(樹)矮
Some of these trees are tall, some are short.
Note that the noun, “tree” in this case, may be omitted after 有的 when it is clear from the context. The above example shows that the noun preceded by 有的 is the subject of the short clauses.
*她在台上放了有的椅子
她在台上放了一些椅子
She placed some chairs on the stage.
The first sentence is ungrammatical because the noun phrase with 有的 is construed as an object of the verb 放. Since a N/NP with 有的 can only be the subject but not the object of a sentence, whereas N/NP with 一些 usually is the object, in this case use the latter.
Reference: Speed Up Your Chinese: Strategies to avoid common errors
