Should folic acid be taken if we are planning for pregnancy ourselves or only with doctor’s suggestion? For how long before conceiving it should be consumed and at what dose?

Yes, folic acid should be consumed at least 3 months prior to planning a pregnancy. Consulting a doctor for pre-conception checkup is advised. However, if you have not been able to do so at least taking folic acid on your own is also advisable. Folic acid comes in different brand names, mostly in 5 mg doses which can be consumed once a day after your meal. (Source : Q&A with Dr.Nira from Yoma's insta live session)