I have reading so many threads but could not get any specific answer, how to construct a workout plan with heavy lifting but not getting bulky, shredded body is the aim without big arms or big thighs. My regular workout is like: 1 body part a day(Back/biceps/chest/triceps/shoulders/legs) with 5 minutes of abs and 15 minutes of cardio in the end. I try to lift heavy with 15-16 reps of 3 sets with rest time 50-60 seconds. I am 90 kg, 6 feet, 31 years old.
how to construct a workout plan with heavy lifting but not getting bulky, shredded body is the aim without big arms or big thighs
Reduce your rep count. As a ballpark up to six reps per set is rather strength regimen, above is hypertrophy (size). Above 12 you are rather in endurance range, but I'd guess, that there is still some extent of hypertrophy.
Furthermore you'll need a considerate amount of protein to grow, think 1-2 g per kg bodyweight per day, which would be at least 90 g protein for you. Gaining heavily will be virtually impossible if you stay well below that, which should not be that hard if you don't eat much meat.
If you want to achieve what you have stated in your question, you need to train more like a weightlifter then a bodybuilder.
Weightlifters train for inner strength first, by keeping set and reps down with maximum weight load, as size it is not the main goal.
If you try to do this, you need to train 3 times a week, as you will need a lot of recovery time.
This is because when you will workout, you will need to keep the intensity up as well, meaning no more then 1 minute between sets.
Also because the majority of the exercises should be multi joint, like clean and jerk, squats and high pulls, with these exercises alone you will also get the cardiovascular workout you need to keep lean.
I am not sure what is "heavy" for you, but for example, I WOULD do a training session like this:
Starting with 1 set of squat with empty Olympic bar of 40 reps.
Then 4 sets of reps to failure with 100kg, 120, 130, 140, 150, even if it is just one rep you can do.
Then clean a jerk by choosing a weight that you can lift over your head only one or 2 times for 4 sets.
Then high pulls with a weight you can do 1 or 2 reps with for 4 sets.
If after this you still have energy, you can do some arms workout, more reps and light weight, it all should not take more then 1 hour.
We are all different, but over the years of training with weightlifter at competition level and bodybuilder, I have learned that there are certain protocols of training that never dies, because they have been proven to be the one that create the best response within people in general, even if at times they can get you bit bored.
Anyway, you can see that what I am suggesting is very well documented on the net, you just need to look at a weightlifter body and a bodybuilder one, to see that the first normally has the body that you are saying you want.
Food wise, you will need to have a good storage of energy before you start, after a few hours from finishing the training and during the rest days, it is when you need to get the protein and vitamins in.