Mnemonic techniques can be incredibly helpful in remembering complex information for the NDA exam. These techniques involve creating associations or connections between new information and something already familiar. Here are some mnemonic techniques that can be used:

1. Acronyms:
- Create an acronym using the first letter of each word or concept you need to remember. For example, to remember the order of military ranks (General, Lieutenant General, Major General, Brigadier, Colonel), create the acronym "GLMBC."
- Associate each letter with a word or phrase that represents the information. This helps in recalling the information more easily.

2. Visualization:
- Create vivid mental images that represent the information you need to remember. For example, if you need to remember the names of different types of tanks, visualize each tank in action or in a specific environment.
- Associate the visual image with the information you want to remember. This creates a strong connection and makes the information more memorable.

3. Chunking:
- Break down complex information into smaller, more manageable chunks. For example, if you need to remember a long sequence of numbers, group them into smaller sets.
- Associate each chunk with a visual image or a keyword that represents the information. This makes it easier to remember and recall the sequence.

4. Rhymes and Songs:
- Create rhymes or songs that incorporate the information you want to remember. Rhymes and songs have a natural rhythm and melody, which can aid in memory recall.
- Repeat the rhyme or song multiple times to reinforce the memory.

5. Method of Loci:
- The method of loci involves associating each piece of information with a specific location or place. Visualize a familiar location, such as your house, and mentally place each piece of information in different rooms or areas.
- As you mentally walk through the location, recall the information associated with each place. The spatial association helps in remembering the information more effectively.

Remember to practice these mnemonic techniques regularly and revise them periodically to reinforce memory retention. Mnemonic techniques are highly individualized, so feel free to adapt and modify them according to your learning style and preferences.