Industrial Engineering

Production / Industrial Engineering are pretty much the same disciplines. The areas of study include production systems (batch / mass / etc. ), production planning and management, economics of production systems, optimization and simulation techniques, etc. The supporting core engineering disciplines like engineering design, machine tools, production technology, thermodynamics, fluid mechanics, strength of materials, material Science, are all taught as well. Manufacturing Systems Engineering is more often a graduate level course rather than an undergraduate course which focuses on production systems and practices, and their mathematical modeling. There is far less emphasis on the supporting engineering disciplines and far more focus on understanding the determinants of efficient manufacturing in different modes of production. In addition, manufacturing processes are studied in detail - from CNC's and other precision machinery, to nanotechnology.

Industrial Electronics is a specialized branch of electronics which deals with the electronic equipment installed in Industry, like manufacturing plants etc. It has a good scope and highly paid jobs are awaiting the candidates. But, Electronics Engineering is a branch of electrical engineering. The discipline studies the use of electromagnetic spectrum in a broad way and is related to the application of electronic devices like integrated circuits, transistors etc. Electronic engineering has a wider scope in terms of number of job opportunities. If you go to Industrial Electronics, it means you are aiming a specific area of the electronics job industry, but that area is definitely highly paid. Best of Luck.

Future scope in this branch or any other branch depends upon how and what you see in that branch.
I am also pursuing metallurgical engineering, and can tell you what I feel about metallurgy.
Well, broadly you can divide this branch in two broad categories:
1. Research
2 Industry
Areas where research is going on in this field are smart materials, sensors, Nano materials and various other areas. And, jobs in this sector mainly include in research institutes and many R&D section of companies like Intel and many more. And, also huge amount of research is done in this field in other countries also (Dakota School of Mines in USA)
There are various types of industries
1 Nonferrous extraction: - VEDANTA, HINDUSTAN ZINC LIMITED, SESA STERALITE, RIO TINTO.
2. Steel plants:-JINDAL STEEL, TATA STEEL
3. Foundries (this is basically a casting industry where gear box housing and various other type of castings are there, which are made in foundries):-MAHINDRA, SWARAJ, TATA MOTORS.
Pay package depend upon various factors, like which company, what position you hold there etc.
It is also true that mostly (not all cases) working conditions are bit tough, as dust, high temperature is there. But, not all the time. One need to be there in such environment.