B.Com

Hi,
It is never tough to do anything.
Everything depends on your mindset and your interest.
If you have interest in it, you should go for it. Nothing will be tough.

Hi Aditi,
No dear, it is not allowed.

Yes, you can definitely take admission in B.Com
Though you won't be getting the top colleges with your score. But, you might end up with some subtle colleges in Pune like:
Ness Wadia College of Commerce, Symbiosis International University, etc.

There is no problem with you pursuing B.Com and MBA after that. You can definitely proceed with the same, but it will be a little difficult for you to catch up as compared to the Commerce students. But, since you seem interested in the course you might catch up fast, if you put in a little bit of extra effort.

You should opt for a Master's degree such as MBA.

First of all, it depends upon the college and second thing is PGDM is more towards practical exposure. Whereas, MBA is of more theoretical. Since you have been from B.com background, if you are really interested in marketing career, then you can choose Marketing with finance (it doesn't matter MBA or PGDM) which will be helpful to get a good job.

Yes, you can get admission in a good college.