What should be the word order after forms of welcher? Should I put the verb at the end of the sentence or is its correct as shown below?
Ich möchte gern wissen, welche Bedingungen soll man erfüllen.
The point is not whether "welche" appears in a sentence. The point is what type of sentence you're forming.
Welche Bedingungen soll man erfüllen?
Ich möchte wissen, welche Bedingungen man erfüllen soll.
As you see, a subordinated clause has the finite verb at the end, while a main clause has it in the second slot of the sentence. All the question words with "w-" can be used to construct both main clauses and subordinated clauses, so they are useless as an indicator of verb position.