HELP!!

The plant has been like this for most of its life, the top leaves seem fine but the bottom fan leaves keep yellowing and dying. Was possibly a nitrogen toxicity due to curling leaves but is in flower now. Possible nutrient deficiency ??
11 weeks old "autoflower" purple mazarr. Had to change lighting to get flowering. Only fed with canna bio vega and flores

This is a paste, the questions are not specific to your situation.
The more information you give the better the help you will get.
How large are your pots?
What medium?
What nutrients, how often and how much is used?
How often do you water and how much water do you use when watering?
What temps and humidity?
Do you have fans for air circulation?
Stuff like that and other info will help.

Unrelated to your question I would ask what type of lighting you use and at what distance from the top of the plant it is. The plant looks good over all if you are new to growing, but looks rather thin in the branches as though maybe your lights are not strong enough. It may have some mild deficiencies, the experts can help you with that but they will need details on your grow..

Are you overwatering?

Yes i am agree with buba, please update with all info so we can help you easily.

It looks like it's growing normally but under low light conditions so the bottom leaves aren't getting enough light to stay green and the plant drops them.

I've grown an auto strain called Purple Jem, (Mazar x LowRyder), a few times and it's a nice bushy kind of plant when grown under 400w MH and HPS lights. Haven't really grow them for size but just for breeding and crossing purposes. The buzz can be pretty good depending on the pheno.