Is it difficuilt to crack interview on service based companies

Generally, no. But it depends on the interviewer. Some can be:-

1. quite knowledgeable and ask tough questions.
2. pragmatic as per the project requirements and ask questions accordingly to see if your skillset matches the role expectations.
3. less knowledgeable and not ask beyond the basics they're aware of or they might ask questions using AI or Google search.
4. pretty immature that they expect answers that match 100% of the answers they have in their minds without considering alternative logic.

Moral of the story: It's better to keep attending interviews for practice and preparation without caring about rejection. The only constraint is if you have enough time to do that along with your regular work and personal responsibilities.