Hello Jyotishree,

Thanks for contacting Careers360.

If your grades are good and, more importantly, you have research experience and relevant coursework, then you can go from a Bachelor's to a PhD immediately . Master's degrees aren't steps in the path of a PhD, but an alternate degree. You can earn an en route Master's in the process of doing your PhD.

Refer to the link below for further information regarding your query:
How to do Phd after Bachelor's degree? Careers360 article

Hope this helps.

Good luck!