Is Panasonic a really good brand? I also have the interest to buy the latest model tv instead of my old Onida tv.
Sony is about the only consistently 'good' brand, but that's mostly because the company has dropped the cheaper TV lines and focused more on the midrange and top-end sets.
Panasonic makes excellent higher-end TVs using LG OLED panels. So does Sony and Philips. They all use LG OLED panels because LG is the only manufacturer of this type (I am excluding QD-OLED). If anything then, Panasonic, Sony and Philips all produce superior OLED TVs to LG despite using LG panels because all three brands have better video processing than LG.
Panasonic LED is a different case.
The company has been struggling in the budget- and mid-market for a number of years. About 18 months ago it decided to cut the loses and outsource its LED TV production to third party manufacturers. AFAIK, it's still Panasonic designed, and I presume overseen by Panasonic, but the company is no longer making its own sets.
Onida is a brand popular in India. From what I have read it started making TVs in India some time in the late 80s or early 90s. This would be when CRT tube TVs were in full swing. The brand became popular because of a clever advertising campaign. The products have been described as "a poor man's Sony", whatever that means.
Since the switch to LCD/LED I can't see much that distinguishes Onida from a Bush, Polaroid, Toshiba, or any other badged product. There's nothing I have seen so far in any specs to suggest that the Onida brand is better than any other budget LED TV.