
Can I take wfh as I’m having 9 month old baby and going to join back from my long leave from April.
Please help with the childcare policy whether can I take WFH despite of project and HR

Check in HR Policy Hub - there's an option of flexible work options for such cases. You can check with HR and refer this Policy to them as well.

Yes policy & hr says project managers should permit, what can I do in that case and how can I select wfh projects

Check with your HR & HRBP. If they ask you to connect with project, loop them in the same email and ask for approval. If they don't, keep including people (cc)up the Organisation structure in mails. And while you're doing all of this, continue WFH if it does not impact your daily activities.
Mam, u can take WFH whenever you feel like if u have a valid reason, ofcourse the validity of the reason will be with the HR. So my simple suggestion is get close to your HRBP and convey your situation.

I asked HRBP, they are telling project managers should give permission so hence im afraid

Yes so there are two level of approval in system once you raise expection request in Ultimatix first it goes to hr and then final approval your manager
You can email your manager first tell him/her reason you want to opt for WFH child care is one of the valid reason Cc: HR
Once that is approved you can raise an exception request