Hiring longterm personal Indian freelancer!!

I am working for 2 firms simultaneously , and sometimes things are hard to perform and complete. I am hiring a freelancer for longterm , he/she can continue his/her freelancing as well , but just need to be available when i am in need. As of first initial 6 months , i will be paying 5000/month and after that 12000-15000/month. No extreme work would be there just small tasks by client's side. And major thing is that she/he should be approachable via whatsapp.

** Mandatory Skils Required -- NodeJs with typescript(mandatory), Redis, Mongodb, Kafka